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Journal articles on the topic 'Ultra luminous IR galaxies'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Tan, Qinghua, Yu Gao, Zhong Wang, and Vivian U. "High resolution SMA imaging of (ultra)-luminous infrared galaxies." Proceedings of the International Astronomical Union 7, S284 (September 2011): 471–74. http://dx.doi.org/10.1017/s1743921312009659.

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AbstractWe present preliminary results on Submillimeter Array (SMA) observations of three Luminous Infrared Galaxies (LIRGs) and one infrared Quasi Stellar Object (IR QSO). The galaxies were observed at sub-kpc spatial resolution in lines of CO and 13CO, as well as in the continuum at 1.3mm. The moment maps show that the molecular gas in these galaxies is distributed in rotating disks with velocity gradients ranging from ~30 to 120 km s−1 kpc−1. Combined with archival CO J=3-2 data, the spatial distributions of the CO J=3-2/J=2-1 ratios shows clear variations across the galaxies. The brightness temperature of the overlap region in VV 114 is found to be lower than that in the nuclear region of VV 114E, suggesting that that the bulk of molecular gas in this region is sub-thermalized.

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Tyson, J. Anthony. "Spectrum and Origin of the Extragalactic Optical Background Radiation." Symposium - International Astronomical Union 139 (1990): 245–55. http://dx.doi.org/10.1017/s0074180900240813.

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Ultra-deep CCD surveys to 29 mag from .32 to .9 μ wavelength reveal an isotropic population of very blue galaxies. There are over 150,000 of these objects per square degree per magnitude. Saturation of their number density at 27 mag indicates that most of the optical light from this population has been detected. The resulting extragalactic background radiation from the UV to the near-IR due to this population of objects is shown. Gravitational lens and Lyman-break observations show that the redshift of galaxies fainter than 24 mag is in the range 1–3. Small-scale dark lane structures may be intergalactic dust clouds or tunnels through the luminous galaxy distribution.

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Hogan, L., D. Rigopoulou, G. E. Magdis, M. Pereira-Santaella, I. García-Bernete, N. Thatte, K. Grisdale, and J.-S. Huang. "Integral field spectroscopy of luminous infrared main-sequence galaxies at cosmic noon." Monthly Notices of the Royal Astronomical Society 503, no. 4 (February 26, 2021): 5329–50. http://dx.doi.org/10.1093/mnras/stab527.

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ABSTRACT We present the results of an integral field spectroscopy survey of a sample of dusty (ultra) luminous infrared galaxies (U/LIRGs) at 2 < z < 2.5 using KMOS on the Very Large Telescope. The sample has been drawn from Herschel deep field surveys and benefits from ancillary multiwavelength data. Our goal is to investigate the physical characteristics, kinematics, and the drivers of star formation in the galaxies whose contribution dominates the peak of the cosmic star formation density. Two-thirds of the sample are main-sequence galaxies in contrast to the starburst nature of local U/LIRGs. Our kinematic study, unique in its focus on z ∼ 2 dusty star-forming galaxies, uses the H α emission line to find that ∼40 per cent appear to be isolated discs based on the ratio of rotational velocity to the velocity dispersion, suggesting steady-state mechanisms are sufficient to power the large star formation rates (SFRs). The ratio of obscured to unobscured star formation indicates the sample of galaxies experiences less dust obscuration compared to intermediate and local counterparts, while also hosting cooler dust than local U/LIRGs. In addition to H α we detect [N ii] 6583 Å in our targets and show the gas-phase metallicities do not exhibit the metal deficiency of local U/LIRGs. These results indicate that, despite their extreme IR luminosity, the underlying mechanisms driving the massive SFRs found at cosmic noon are due to scaled up disc galaxies as opposed to mergers.

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Greve, Thomas R. "Probing star formation relations of mergers and normal galaxies across the CO ladder." Proceedings of the International Astronomical Union 11, S315 (August 2015): 49–52. http://dx.doi.org/10.1017/s1743921316007249.

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AbstractWe examine integrated luminosity relations between the IR continuum and the CO rotational ladder observed for local (ultra) luminous infra-red galaxies ((U)LIRGs, LIR ≥ 1011 M⊙) and normal star forming galaxies in the context of radiation pressure regulated star formation proposed by Andrews & Thompson (2011). This can account for the normalization and linear slopes of the luminosity relations (log LIR = α log L'CO + β) of both low- and high-J CO lines observed for normal galaxies. Super-linear slopes occur for galaxy samples with significantly different dense gas fractions. Local (U)LIRGs are observed to have sub-linear high-J (Jup > 6) slopes or, equivalently, increasing LCOhigh-J/LIR with LIR. In the extreme ISM conditions of local (U)LIRGs, the high-J CO lines no longer trace individual hot spots of star formation (which gave rise to the linear slopes for normal galaxies) but a more widespread warm and dense gas phase mechanically heated by powerful supernovae-driven turbulence and shocks.

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Klaas, U., M. Haas, S. A. H. Müller, R. Chini, B. Schulz, I. Coulson, H. Hippelein, K. Wilke, M. Albrecht, and D. Lemke. "Infrared to millimetre photometry of ultra-luminous IR galaxies : New evidence favouring a 3-stage dust model." Astronomy & Astrophysics 379, no. 3 (December 2001): 823–44. http://dx.doi.org/10.1051/0004-6361:20011377.

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6

Ricci, C., G. C. Privon, R. W. Pfeifle, L. Armus, K. Iwasawa, N. Torres-Albà, S. Satyapal, et al. "A hard X-ray view of luminous and ultra-luminous infrared galaxies in GOALS – I. AGN obscuration along the merger sequence." Monthly Notices of the Royal Astronomical Society 506, no. 4 (July 19, 2021): 5935–50. http://dx.doi.org/10.1093/mnras/stab2052.

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ABSTRACT The merger of two or more galaxies can enhance the inflow of material from galactic scales into the close environments of active galactic nuclei (AGNs), obscuring and feeding the supermassive black hole (SMBH). Both recent simulations and observations of AGN in mergers have confirmed that mergers are related to strong nuclear obscuration. However, it is still unclear how AGN obscuration evolves in the last phases of the merger process. We study a sample of 60 luminous and ultra-luminous IR galaxies (U/LIRGs) from the GOALS sample observed by NuSTAR. We find that the fraction of AGNs that are Compton thick (CT; $N_{\rm H}\ge 10^{24}\rm \, cm^{-2}$) peaks at $74_{-19}^{+14}{{\ \rm per\ cent}}$ at a late merger stage, prior to coalescence, when the nuclei have projected separations (dsep) of 0.4–6 kpc. A similar peak is also observed in the median NH [$(1.6\pm 0.5)\times 10^{24}\rm \, cm^{-2}$]. The vast majority ($85^{+7}_{-9}{{\ \rm per\ cent}}$) of the AGNs in the final merger stages (dsep ≲ 10 kpc) are heavily obscured ($N_{\rm H}\ge 10^{23}\rm \, cm^{-2}$), and the median NH of the accreting SMBHs in our sample is systematically higher than that of local hard X-ray-selected AGN, regardless of the merger stage. This implies that these objects have very obscured nuclear environments, with the $N_{\rm H}\ge 10^{23}\rm \, cm^{-2}$ gas almost completely covering the AGN in late mergers. CT AGNs tend to have systematically higher absorption-corrected X-ray luminosities than less obscured sources. This could either be due to an evolutionary effect, with more obscured sources accreting more rapidly because they have more gas available in their surroundings, or to a selection bias. The latter scenario would imply that we are still missing a large fraction of heavily obscured, lower luminosity ($L_{2-10}\lesssim 10^{43}\rm \, erg\, s^{-1}$) AGNs in U/LIRGs.

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Richards, A. M. S., R. J. Cohen, G. H. Cole, A. J. Holloway, A. Pedlar, J. L. Collett, J. H. Knapen, et al. "Circumnuclear Dynamics in Mrk 273 and Mrk 231." Symposium - International Astronomical Union 205 (2001): 212–15. http://dx.doi.org/10.1017/s0074180900221001.

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Markarian 273 and Markarian 231 are ultra-luminous IR galaxies which show signs of merger activity. Their radio continuum and spectral line emission has been imaged on scales of tens of parsec using MERLIN. Mrk 273 and Mrk 231 are classed as Seyfert types 2 and 1 respectively. The distribution and velocity gradients shown by OH masers and HI absorption are consistent with material in a rotating disk or ring, with the axis at greater than 45° to the line of sight in Mrk 273, and at less than 45° to the line of sight in Mrk 231. We estimate the amount of mass enclosed and infer its distribution from irregularities in the maser morphologies and comparison with HI and radio continuum data.

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Mickaelian, Areg M., and Gohar S. Harutyunyan. "Study of the Byurakan-IRAS galaxy sample." Proceedings of the International Astronomical Union 8, S292 (August 2012): 159. http://dx.doi.org/10.1017/s1743921313000896.

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AbstractThe Byurakan-IRAS Galaxy (BIG) sample (Mickaelian 1995) is the result of optical identifications of IRAS PSC sources at high-galactic latitudes using the First Byurakan Survey (FBS) low-dispersion spectra (Markarian et al. 1989). Among the 1577 objects 1178 galaxies have been identified. Most are dusty spiral galaxies and there are a number of ULIRGs among these objects. Our spectroscopic observations carried out with three telescopes (Byurakan Astrophysical Observatory 2.6m, Russian Special Astrophysical Observatory 6m and Observatoire de Haute Provence 1.93m) (Mickaelian & Sargsyan 2010) for 172 galaxies, as well as the SDSS DR8 spectra for 83 galaxies make up the list of 255 spectroscopically studied BIG objects. The classification to activity types for narrow-line emission galaxies has been carried out using the diagnostic diagrams by Veilleux & Osterbrock (1987). All possible physical characteristics have been measured and/or calculated, including radial velocities and distances, angular and physical sizes, absolute magnitudes and luminosities (both optical and IR). IR luminosities and star-formation rates have been calculated from the IR fluxes (Duc et al. 1997).Among the 172 observed galaxies, 102 starburst (HII) ones, 29 AGN (Sy or LINER), and 19 galaxies with composite spectrum have been revealed; spectra of 12 galaxies show emission features but without a possibility for more accurate classification, 9 galaxies are presented as galaxies where the star formation rate does not exceed normal one, and 1 galaxy is an absorption galaxy. Among the 83 objects having SDSS spectra, there are 55 HIIs, 8 Seyferts, 2 LINERs, 4 other AGN (without accurate classification), 6 composite spectrum objects and 8 other emission-line galaxies. In our spectroscopic sample we have 43 (17%) AGN, 25 (10%) composite spectrum objects, 157 (62%) starbursts, 29 emission-line galaxies without a definite type, and 1 absorption-line galaxy. There are 3 Ultra-Luminous InfraRed Galaxies (ULIRG).Various multiwavelength (MW) data have been retrieved for the full sample of 1178 objects from recent catalogs from X-ray to radio (ROSAT, GALEX, APM, MAPS, USNO, GSC, SDSS, 2MASS, WISE, IRAS, AKARI, NVSS, FIRST, etc.) to make a complete study of these galaxies possible. MW SEDs have been built, which have been matched to their optical classifications. Star-formation rates have been calculated to compare to their other physical characteristics, such as morphology, activity types, UV, optical, IR and radio luminosities, etc.

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Ramón-Pérez, Marina, Ángel Bongiovanni, Ana María Pérez García, Jordi Cepa, Jakub Nadolny, Irene Pintos-Castro, Maritza A. Lara-López, et al. "The OTELO survey." Astronomy & Astrophysics 631 (October 14, 2019): A11. http://dx.doi.org/10.1051/0004-6361/201833296.

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Aims. We take advantage of the capabilities of the OSIRIS Tunable Emission Line Object (OTELO) survey to select and study the AGN population in the field. In particular, we aim to perform an analysis of the properties of these objects, including their demography, morphology, and IR luminosity. Focusing on the population of Hα emitters at z ∼ 0.4, we also aim to study the environments of AGN and non-AGN galaxies at that redshift. methods. We make use of the multiwavelength catalogue of objects in the field compiled by the OTELO survey, unique in terms of minimum flux and equivalent width. We also take advantage of the pseudo-spectra built for each source, which allow the identification of emission lines and the discrimination of different types of objects. Results. We obtained a sample of 72 AGNs in the field of OTELO, selected with four different methods in the optical, X-rays, and mid-infrared bands. We find that using X-rays is the most efficient way to select AGNs. An analysis was performed on the AGN population of OTELO in order to characterise its members. At z ∼ 0.4, we find that up to 26% of our Hα emitters are AGNs. At that redshift, AGNs are found in identical environments to non-AGNs, although they represent the most clustered group when compared to passive and star-forming galaxies. The majority of our AGNs at any redshift were classified as late-type galaxies, including a 16% proportion of irregulars. Another 16% of AGNs show signs of interactions or mergers. Regarding the infrared luminosity, we are able to recover all the luminous infrared galaxies (LIRGs) in the field of OTELO up to z ∼ 1.6. We find that the proportion of LIRGs and ultra-luminous infraed galaxies (ULIRGs) is higher among the AGN population, and that ULIRGs show a higher fraction of AGNs than LIRGs.

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Penney, J. I., A. W. Blain, R. J. Assef, T. Diaz-Santos, J. González-López, C.-W. Tsai, M. Aravena, et al. "Cold molecular gas and free–free emission from hot, dust-obscured galaxies at z ∼ 3." Monthly Notices of the Royal Astronomical Society 496, no. 2 (June 6, 2020): 1565–78. http://dx.doi.org/10.1093/mnras/staa1582.

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ABSTRACT We report on observations of redshifted CO(1–0) line emission and observed-frame $\rm \sim 30\,$GHz radio continuum emission from five ultra-luminous, mid-IR selected hot, Dust-Obscured Galaxies (Hot DOGs) at $z\rm \gtrsim 3$ using the Karl G. Jansky Very Large Array. We detect CO(1–0) line emission in all five Hot DOGs, with one of them at high signal-to-noise ratio. We analyse FIR-radio spectral energy distributions, including dust, free–free, and synchrotron emission for the galaxies. We find that most of the $\rm 115\,$ GHz rest-frame continuum is mostly due to synchrotron or free–free emission, with only a potentially small contribution from thermal emission. We see a deficit in the rest-frame $\rm 115\,$ GHz continuum emission compared to dusty star-forming galaxies and sub-millimetre galaxies (SMGs) at high redshift, suggesting that Hot DOGs do not have similar cold gas reserves compared with star-forming galaxies. One target, W2305−0039, is detected in the FIRST $\rm 1.4\, GHz$ survey, and is likely to possess compact radio jets. We compare to the FIR–radio correlation, and find that at least half of the Hot DOGs in our sample are radio-quiet with respect to normal galaxies. These findings suggest that Hot DOGs have comparably less cold molecular gas than star-forming galaxies at lower, $z\rm \sim 2$ redshifts, and are dominated by powerful, yet radio-quiet AGN.

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Gruppioni, C., M. Béthermin, F. Loiacono, O. Le Fèvre, P. Capak, P. Cassata, A. L. Faisst, et al. "The ALPINE-ALMA [CII] survey." Astronomy & Astrophysics 643 (October 27, 2020): A8. http://dx.doi.org/10.1051/0004-6361/202038487.

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Aims. We present the detailed characterisation of a sample of 56 sources serendipitously detected in ALMA band 7 as part of the ALMA Large Program to INvestigate CII at Early Times (ALPINE). These sources, detected in COSMOS and ECDFS, have been used to derive the total infrared luminosity function (LF) and to estimate the cosmic star formation rate density (SFRD) up to z ≃ 6. Methods. We looked for counterparts of the ALMA sources in all the available multi-wavelength (from HST to VLA) and photometric redshift catalogues. We also made use of deeper UltraVISTA and Spitzer source lists and maps to identify optically dark sources with no matches in the public catalogues. We used the sources with estimated redshifts to derive the 250 μm rest-frame and total infrared (8–1000 μm) LFs from z ≃ 0.5 to 6. Results. Our ALMA blind survey (860 μm flux density range: ∼0.3–12.5 mJy) allows us to further push the study of the nature and evolution of dusty galaxies at high-z, identifying luminous and massive sources to redshifts and faint luminosities never probed before by any far-infrared surveys. The ALPINE data are the first ones to sample the faint end of the infrared LF, showing little evolution from z ≃ 2.5 to z ≃ 6, and a “flat” slope up to the highest redshifts (i.e. 4.5 < z < 6). The SFRD obtained by integrating the luminosity function remains almost constant between z ≃ 2 and z ≃ 6, and significantly higher than the optical or ultra-violet derivations, showing a significant contribution of dusty galaxies and obscured star formation at high-z. About 14% of all the ALPINE serendipitous continuum sources are found to be optically and near-infrared (near-IR) dark (to a depth Ks ∼ 24.9 mag). Six show a counterpart only in the mid-IR and no HST or near-IR identification, while two are detected as [C II] emitters at z ≃ 5. The six HST+near-IR dark galaxies with mid-IR counterparts are found to contribute about 17% of the total SFRD at z ≃ 5 and to dominate the high-mass end of the stellar mass function at z > 3.

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Fox, Ori D., and Chad Casper. "A Spitzer Search for the Missing Supernovae in the Galactic Nuclei of ULIRGS." Proceedings of the International Astronomical Union 11, A29B (August 2015): 238. http://dx.doi.org/10.1017/s1743921316005111.

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AbstractSupernova (SN) rates serve as an important probe of star formation models and initial mass functions, particularly at high redshifts due to the SN intrinsic luminosity. Ground-based optical surveys, however, typically discover nearly ten times fewer SNe than predicted, challenging our understanding of massive star formation and evolution. These results are generally attributed to the high dust extinction associated with the nuclei of star forming galaxies, such as Ultra Luminous InfraRed Galaxies (ULIRGs). Near-infrared surveys have been unsuccessful due to extinction values exceeding AV > 25 mag, and even on an 8-m AO system, subtraction algorithms used to find the SNe inevitably leave large residuals associated with the inner 2” of the galactic nucleus, which is where a majority of the SNe occur. A successful survey must be conducted at longer wavelengths and with a space-based telescope, which has stable seeing that reduces the necessity for any subtraction algorithms and, therefore, residuals. Here we present ongoing work from our 300 hour Spitzer 3.6 micron survey for dust-extinguished SNe in the nuclear regions of ULIRGs within 200 Mpc. The direct product of this study will be an improved understanding of the connection between the far-IR luminosity of ULIRGs and massive star formation.

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Ueda, Junko, Daisuke Iono, Min S. Yun, Tomonari Michiyama, Yoshimasa Watanabe, Ronald L. Snell, Daniel Rosa-González, Toshiki Saito, Olga Vega, and Takuji Yamashita. "Cold Molecular Gas in Merger Remnants. II. The Properties of Dense Molecular Gas." Astrophysical Journal Supplement Series 257, no. 2 (December 1, 2021): 57. http://dx.doi.org/10.3847/1538-4365/ac257a.

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Abstract We present the 3 mm wavelength spectra of 28 local galaxy merger remnants obtained with the Large Millimeter Telescope. Sixteen molecular lines from 14 different molecular species and isotopologues were identified, and 21 out of 28 sources were detected in one or more molecular lines. On average, the line ratios of the dense gas tracers, such as HCN (1–0) and HCO+(1–0), to 13CO (1–0) are 3–4 times higher in ultra/luminous infrared galaxies (U/LIRGs) than in non-LIRGs in our sample. These high line ratios could be explained by the deficiency of 13CO and high dense gas fractions suggested by high HCN (1–0)/12CO (1–0) ratios. We calculate the IR-to-HCN (1–0) luminosity ratio as a proxy of the dense gas star formation efficiency. There is no correlation between the IR/HCN ratio and the IR luminosity, while the IR/HCN ratio varies from source to source ((1.1–6.5) × 103 L ☉/(K km s−1 pc2)). Compared with the control sample, we find that the average IR/HCN ratio of the merger remnants is higher by a factor of 2–3 than those of the early/mid-stage mergers and nonmerging LIRGs, and it is comparable to that of the late-stage mergers. The IR-to-12CO (1–0) ratios show a similar trend to the IR/HCN ratios. These results suggest that star formation efficiency is enhanced by the merging process and maintained at high levels even after the final coalescence. The dynamical interactions and mergers could change the star formation mode and continue to impact the star formation properties of the gas in the postmerger phase.

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Hughes, D. H., J. S. Dunlop, E. I. Robson, and W. K. Gear. "Submillimetre Spectral Indices of Radio-Quiet Quasars." Symposium - International Astronomical Union 159 (1994): 324. http://dx.doi.org/10.1017/s0074180900175291.

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Hughes etal. (1993) have made submillimetre continuum observations of 10 IRAS selected radio-quiet quasars (RQQs). Three RQQs, I Zw 1, Mrk1014 and Mrk376, have been detected at 800 and 450μm using the 3He bolometer UKT14 on t he 15-m James Clerk Maxwell telescope. These submillimetre data, together with existing 1.3 mm observations (Chini etal. 1989) demonstrate that the measured submillimetre spectral indices, 〈αsm〉 = 3.8 ± 0.5, significantly exceed the critical theoretical limit of αsm = 2.5 predicted for the self-absorption of synchrotron emission. This result is independent of any contributions to the 100μm IRAS fluxes from cirrus emission in the host galaxies, extended circumnucl ear starformation and FIR emission from companion or confusing sources. All current non-thermal models (de Kool & Begelman 1989, Schlickeiser etal. 1991) are rejected in favour of the alternative explanation that the FIR luminosity is dominated by thermal emission from warm (45–60 K) dust grains. The submillimetre optical depth and source-size for the thermal emission cannot yet be constrained by these data and, as a result, no discrimination can be made between dust heated by an extended (> 1 kpc) starburst region or a central compact luminosity source. However ground-based imaging observations at mid-IR wavelengths and FIR photometry (60–200μm) with the KAO are currently in progress specifically to address this problem. The high gas masses (> 1010M⊙) in RQQs inferred from the submillimetre continuum observations are in agreement with the H2 masses determined from CO measurements. Alternatively the results show that the MH2/Mdust ratio measured in RQQs (∼ 370 ± 150) is consistent with that measured in spiral galaxies and ultra-luminous IRAS galaxies.

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Simon, Leah E., and Fred Hamann. "Tracing Metallicity in High Redshift Quasars." Proceedings of the International Astronomical Union 5, S265 (August 2009): 183–84. http://dx.doi.org/10.1017/s1743921310000517.

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AbstractWe present two ongoing studies of gas phase abundances around high redshift quasars. First, we examine broad emission line (BEL) metallicities for 29 quasars with 2.3 < z < 4.6 and far-infrared (far-IR) luminosities (LFIR) from 1013.4 to ≤ 1012.2 L⊙, corresponding to star formation rates (SFRs) of 6740 to ≤ 1360 M⊙ yr−1. Quasar samples sorted by LFIR might represent an evolutionary sequence if SFRs in quasar hosts generally diminish across quasar lifetimes. We create three composite spectra from rest-frame ultra-violet Sloan Digital Sky Survey spectra with increasing far-IR luminosity. We measure the N V(λ1240)/C IV(λ1550) and Si IV(λ1397)+O IV](λ1402)/C IV(λ1550) emission line flux ratios for each composite and find uniformly high (~5-10 times solar) metallicities for the three composites, and no evidence for changes in metal enrichment with changes in ongoing SFR. Second, we present preliminary results from the largest ever survey of high resolution associated absorption line (AAL) region metallicities and physical properties in a sample of high redshift (z > 3) quasars. This includes five quasars with previously known AALs at z > 4 and two well measured z ~3 quasars with unusually rich absorption spectra. We determine well-constrained metallicities of about twice solar for five AAL systems. We find a range of lower limits for AAL metallicities in the z > 4 quasars from 1/100ths solar to 3 times solar. Overall, these results for typically super-solar gas-phase metallicities near quasars are consistent with evolutionary schemes where the major episodes of star formation in the host galaxies occur before the visibly luminous quasar phase. High SFRs (comparable to ULIRGs) in the host galaxies are not clearly linked to younger or chemically less mature quasar environments.

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Song, Y., S. T. Linden, A. S. Evans, L. Barcos-Muñoz, E. J. Murphy, E. Momjian, T. Díaz-Santos, et al. "Characterizing Compact 15–33 GHz Radio Continuum Sources in Local U/LIRGs." Astrophysical Journal 940, no. 1 (November 1, 2022): 52. http://dx.doi.org/10.3847/1538-4357/ac923b.

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Abstract We present the analysis of ∼100 pc scale compact radio continuum sources detected in 63 local (ultra)luminous infrared galaxies (U/LIRGs; L IR ≥ 1011 L ⊙), using FWHM ≲ 0.″1–0.″2 resolution 15 and 33 GHz observations with the Karl G. Jansky Very Large Array. We identify a total of 133 compact radio sources with effective radii of 8–170 pc, which are classified into four main categories—“AGN” (active galactic nuclei), “AGN/SBnuc” (AGN-starburst composite nucleus), “SBnuc” (starburst nucleus), and “SF” (star-forming clumps)—based on ancillary data sets and the literature. We find that “AGN” and “AGN/SBnuc” more frequently occur in late-stage mergers and have up to 3 dex higher 33 GHz luminosities and surface densities compared with “SBnuc” and “SF,” which may be attributed to extreme nuclear starburst and/or AGN activity in the former. Star formation rates (SFRs) and surface densities (ΣSFR) are measured for “SF” and “SBnuc” using both the total 33 GHz continuum emission (SFR ∼ 0.14–13 M ⊙ yr−1, ΣSFR ∼ 13–1600 M ⊙ yr−1 kpc−2) and the thermal free–free emission from H ii regions (median SFRth ∼ 0.4 M ⊙ yr−1, Σ SFR th ∼ 44 M ⊙ yr−1 kpc−2). These values are 1–2 dex higher than those measured for similar-sized clumps in nearby normal (non-U/LIRGs). The latter also have a much flatter median 15–33 GHz spectral index (∼−0.08) compared with “SBnuc” and “SF” (∼−0.46), which may reflect higher nonthermal contribution from supernovae and/or interstellar medium densities in local U/LIRGs that directly result from and/or lead to their extreme star-forming activities on 100 pc scales.

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Fairclough, J. H. "New ultra-luminous galaxies." Monthly Notices of the Royal Astronomical Society 219, no. 1 (March 1, 1986): 1P—4P. http://dx.doi.org/10.1093/mnras/219.1.1p.

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Tekola, Abiy G., Petri Väisänen, and Andreas Berlind. "The Environments of Luminous IR Galaxies." Proceedings of the International Astronomical Union 6, S277 (December 2010): 17–20. http://dx.doi.org/10.1017/s174392131102237x.

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AbstractWe have studied the star formation vs. environment connection of local LIRGs by characterising their environment using number densities of galaxies as well as halo masses. It is found that LIRGs preferentially live in group environments and that they also exhibit a relation where their star formation rate increases with their environmental density.

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Mushotzky, Richard. "Ultra-Luminous Sources in Nearby Galaxies." Progress of Theoretical Physics Supplement 155 (2004): 27–44. http://dx.doi.org/10.1143/ptps.155.27.

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Partridge, R. B., J. Marr, T. Crawford, and M. Strauss. "What Powers Ultra-Luminous IRAS Galaxies?" Symposium - International Astronomical Union 175 (1996): 215–16. http://dx.doi.org/10.1017/s0074180900080554.

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I report here centimeter–wavelength observations carried out at the Very Large Array (VLA) to help resolve two questions. First, what is the source of the far infrared (FIR) emission in infrared-luminous IRAS galaxies, active nuclei or more widely distributed star formation? And what physics underlies the tight correlation (Helou et al., 1985) between FIR and radio flux? To test potential answers to these questions, we believe it is important to study the most luminous IRAS galaxies. We selected 39 for study from the ultraluminous catalog of Strauss et al.(1990 and 1992). All sources had FIR luminosity ≥ 1011.4 L⊙. Radio wavelength observations of these systems provide several advantages. First, in the radio there is no obscuration, so we can “see” the active galactic nuclei, if present. Radio spectral indices can distinguish between synchrotron and thermal emission. And finally, observations at the VLA provide sub–kpc resolution. We observed these sources with the VLA in its C configuration. At 1460 MHz, the effective resolution was ≃ 15″; and ≃ 4″ at 4860 MHz. We made follow-up observations on 24 sources in the A configuration with resolution at 4860 MHz of ≃ 0″.5 (or 300–800 h–1 pc for these sources).

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Mushotzky, Richard. "Ultra-luminous sources in nearby galaxies." Advances in Space Research 38, no. 12 (January 2006): 2793–800. http://dx.doi.org/10.1016/j.asr.2006.08.005.

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Leão, João Rodrigo S., and Claus Leitherer. "A Spitzer study of interacting luminous and ultra-luminous infrared galaxies." Proceedings of the International Astronomical Union 7, S284 (September 2011): 202–4. http://dx.doi.org/10.1017/s1743921312009738.

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AbstractWe conducted a Spitzer Space Telescope survey of 28 Luminous (11 < log (LIR/L⊙) < 12, LIRGs) and Ultra-Luminous Infrared Galaxies (log (LIR/L⊙) > 12, ULIRGs). Many of these galaxies are found in pairs or associations and are powered by either nuclear activity or star-formation (Sanders & Mirabel 1996). Our main goal is to understand the relative importance of starbursts and AGNs in interacting systems. Is the frequency of AGN and starbursts in these interacting galaxies related to their luminosities? What is the importance of the merger stage and the frequency of AGNs? We present our conclusions and diagnostic diagrams based in the observed near infrared lines and compare to studies based solely in optical data.

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23

Gao, Yu. "Luminous IR Galaxies: Evolution and Molecular Gas." International Astronomical Union Colloquium 159 (1997): 439–40. http://dx.doi.org/10.1017/s0252921100040690.

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Luminous infrared galaxies (LIRGs), denned by the criterion LIR ≳ 2 × 1011L⊙ (for H0=75 kms−1 Mpc−1), are the most powerful IR sources in the Universe, with most of their emission (~ 90%) in the far-IR. Most LIRGs are interacting/merging galaxies with large amounts of molecular gas as revealed by CO surveys (Sanders et al. 1991; Solomon et al. 1996). However, whether starbursts or dust-enshrouded AGNs/QSOs dominate the IR luminosity is not resolved.CO may not trace the active star-forming regions where gas density is more than one order of magnitude higher than the average. Dense molecular gas is better traced by high dipole-moment molecules like HCN and CS (e.g., Nguyen-Q-Rieu et al. 1992; Gao & Solomon 1996). Therefore, it is essential to survey HCN emission in a large sample of LIRGs to better reveal the nature of LIRGs. We here study IR and molecular gas properties vs. galaxy-galaxy interactions in LIRGs over various merging phases to trace their evolution and explore some links among interactions, starbursts, and AGN phenomena.

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Clements, D. L., A. C. Baker, and C. J. Lidman. "The Host Galaxies of IR Luminous Quasars." Symposium - International Astronomical Union 186 (1999): 350. http://dx.doi.org/10.1017/s0074180900112975.

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A connection is suspected between quasars and ultraluminous IR galaxies (ULIRGs). Almost all ULIRG activity is triggered by mergers (e.g. Clements et al. 1996, MNRAS, 279, 477). We thus investigate the relationship between quasars and ULIRGs by examining the relationship between FIR luminosity and host morphology in quasars. We use the z < 0.3 imaging survey of PG quasars by McLeod & Rieke (1994, ApJ, 420, 58; 431, 137), and ancillary data, to determine which quasars in the survey have disturbed hosts. This is combined with FIR data from Sanders et al. (1989, ApJ, 347, 29). We apply Survival Analysis techniques to see if the FIR luminosity of the disturbed and undisturbed host quasars differ. We find, with 99.99% confidence, that the disturbed host quasars have higher FIR luminosity. We observe a small, but complete, sample of six quasars selected to have LFIR > 1011.8L⊙, and a comparison sample of quasars with similar redshifts and B-band absolute magnitudes, but without detected FIR emission. At least 3 of the FIR luminous quasars are found in disturbed hosts while the non-FIR luminous quasars all lie in undisturbed hosts. The FIR luminosity in ULIRGs is triggered by interactions. If ULIRGs evolve into quasars we would expect FIR luminous quasars to be younger, and to share more characteristics with ULIRGs, especially disturbed host morphology. These studies are consistent with this model for quasar evolution.

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Leão, João Rodrigo S., Patrícia Hepp, and Claus Leitherer. "Buried AGNs and Starbursts in Luminous and Ultra-Luminous Infrared Galaxies." Proceedings of the International Astronomical Union 5, S267 (August 2009): 116. http://dx.doi.org/10.1017/s1743921310005776.

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AbstractWe present the first results of a Spitzer Space Telescope survey of 28 LIRGs and ULIRGs. We used infrared emission lines to separeate AGN and starburst powered systems. We find strong evidence that the incidence of nuclear activity increases with infrared luminosity.

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26

Soria, Roberto. "X-ray Properties of Spiral Galaxies." Symposium - International Astronomical Union 214 (2003): 59–69. http://dx.doi.org/10.1017/s0074180900194161.

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X-ray studies of nearby spiral galaxies with star formation allow us to investigate temperature and spatial distribution of the hot diffuse plasma, and to carry out individual and statistical studies of different classes of discrete sources (low- and high-mass X-ray binaries, Supernova remnants, supersoft and ultra-luminous sources). In particular, we briefly review the different models proposed to explain the ultra-luminous sources. We can then use the X-ray properties of a galaxy to probe its star formation history. We choose the starburst spiral M83 to illustrate some of these issues.

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27

Gallimore, Jack F., and William C. Keel. "Statistics of Associations Among IR Galaxies." International Astronomical Union Colloquium 124 (1990): 353–56. http://dx.doi.org/10.1017/s0252921100005340.

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In the course of expanding the search of Kleinmann et.al. (1988) for distant, infrared-luminous objects, we noticed (as is often remarked) that a large number of infrared-selected galaxies have close neighbors or show merger characteristics (e.g. tidal tails, distorted disks). Because the sample size is large (567 infrared galaxies and 2182 field galaxies), this sample is ideal for statistically examining the importance of interactions among infrared galaxies. In particular, we compare the nearest-neighbor distribution and the two-point correlation function of our sample with that of a control sample of field galaxies.

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Sivaram, C., K. Arun, and O. V. Kiren. "Bioenergetics and stellar luminosities." International Journal of Astrobiology 18, no. 3 (October 12, 2017): 211–12. http://dx.doi.org/10.1017/s1473550417000386.

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AbstractWe draw attention to a curious coincidence wherein the most (steadily emitting) luminous objects in the Universe from stellar X-ray sources to ultra-luminous quasars and Ultra Luminous Infrared Galaxies, steadily emit a power per unit mass, which is just the same value as the maximal metabolic rate in (warm-blooded) bio-organisms.

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Gao, Y., and P. M. Solomon. "CO Observations of Luminous IR Galaxy Mergers." Symposium - International Astronomical Union 186 (1999): 275–76. http://dx.doi.org/10.1017/s0074180900112756.

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Luminous starbursts are observed to occur mostly as a result of a collision/merger in gas-rich galaxies, and most luminous infrared galaxies (LIGs) are indeed gas-rich mergers. In order to determine the relationship between the IR and molecular gas properties and the galaxy-galaxy interactions, we study LIG mergers in the intermediate merging process. We have observed nearly 20 LIG mergers and together with the CO data in the literature, we have found a correlation between the CO luminosity, LCO, and the projected separation of merger nuclei, RSep, in > 50 LIG mergers. The correlation suggests the molecular content is decreasing as merging advances and is better established with ~ 40 LIG mergers excluding ultraluminous ones, which resembles more a volume-limited, statistically complete sample of LIG mergers. In addition, an anti-correlation between LIR/LCO (the measure of star formation efficiency, SFE) and RSep is evident. One interpretation is that the molecular gas content of LIG mergers is being rapidly depleted due to the merger-induced starbursts and the increase of SFE as merging progresses.

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Silk, Joseph. "Ultra-diffuse galaxies without dark matter." Monthly Notices of the Royal Astronomical Society: Letters 488, no. 1 (July 1, 2019): L24—L28. http://dx.doi.org/10.1093/mnrasl/slz090.

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ABSTRACT I develop a high-velocity galaxy collision model to explain a rare but puzzling phenomenon, namely the apparent existence of ultra-diffuse galaxies with little dark matter. Predictions include simultaneous triggering of overpressured dense clouds to form luminous old globular clusters, a protogroup environment to generate high relative velocities of the initially gas-rich galaxies in the early universe, and spatially separated dark haloes, possibly detectable via gravitational lensing and containing relic low-metallicity stars with enhanced α/Fe at ultra-low surface brightness.

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31

Durkalec, A., O. Le Fèvre, A. Pollo, G. Zamorani, B. C. Lemaux, B. Garilli, S. Bardelli, et al. "The VIMOS Ultra Deep Survey." Astronomy & Astrophysics 612 (April 2018): A42. http://dx.doi.org/10.1051/0004-6361/201730734.

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We present a study of the dependence of galaxy clustering on luminosity and stellar mass in the redshift range 2 < z < 3.5 using 3236 galaxies with robust spectroscopic redshifts from the VIMOS Ultra Deep Survey (VUDS), covering a total area of 0.92 deg2. We measured the two-point real-space correlation function wp(rp) for four volume-limited subsamples selected by stellar mass and four volume-limited subsamples selected by MUV absolute magnitude. We find that the scale-dependent clustering amplitude r0 significantly increases with increasing luminosity and stellar mass. For the least luminous galaxies (MUV < −19.0), we measured a correlation length r0 = 2.87 ± 0.22 h−1 Mpc and slope γ = 1.59 ± 0.07, while for the most luminous (MUV < −20.2) r0 = 5.35 ± 0.50 h−1 Mpc and γ = 1.92 ± 0.25. These measurements correspond to a strong relative bias between these two subsamples of Δb∕b* = 0.43. Fitting a five-parameter halo occupation distribution (HOD) model, we find that the most luminous (MUV < −20.2) and massive (M⋆ > 1010 h−1 M⊙) galaxies occupy the most massive dark matter haloes with ⟨Mh⟩ = 1012.30 h−1 M⊙. Similar to the trends observed at lower redshift, the minimum halo mass Mmin depends on the luminosity and stellar mass of galaxies and grows from Mmin = 109.73 h−1 M⊙ to Mmin = 1011.58 h−1 M⊙ from the faintest to the brightest among our galaxy sample, respectively. We find the difference between these halo masses to be much more pronounced than is observed for local galaxies of similar properties. Moreover, at z ~ 3, we observe that the masses at which a halo hosts, on average, one satellite and one central galaxy is M1 ≈ 4Mmin over all luminosity ranges, which is significantly lower than observed at z ~ 0; this indicates that the halo satellite occupation increases with redshift. The luminosity and stellar mass dependence is also reflected in the measurements of the large-scale galaxy bias, which we model as bg,HOD (>L) = 1.92 + 25.36(L/L*)7.01. We conclude our study with measurements of the stellar-to-halo mass ratio (SHMR). We observe a significant model-observation discrepancy for low-mass galaxies, suggesting a higher than expected star formation efficiency of these galaxies.

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32

Gao, Y., R. A. Gruendl, C. Y. Hwang, and K. Y. Lo. "Luminous IR Galaxies in a Merger Sequence: Bima Co Imaging." Symposium - International Astronomical Union 186 (1999): 227–30. http://dx.doi.org/10.1017/s0074180900112677.

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The power output in luminous infrared galaxies (LIGs, LIR ≳ 1011L⊙, H0 = 75 kms−1 Mpc−1) can approach the bolometric luminosity of quasars and can be provided by either starbursts or dust-enshouded QSOs, or both. Most LIGs appear to comprise of mergers of gas-rich galaxies. So, intense bursts of star formation apparently result from interaction and merging of galaxies, but the exact physical processes involved in collecting the large amount of gas involved and in initiating the starbursts are not well understood.

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Aalto, S., A. G. Polatidis, S. Hüttemeister, and S. J. Curran. "CN and HNC line emission in IR luminous galaxies." Astronomy & Astrophysics 381, no. 3 (January 2002): 783–94. http://dx.doi.org/10.1051/0004-6361:20011514.

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34

Tutui, Yoshinori, Yoshiaki Sofue, Mareki Honma, Takashi Ichikawa, and Ken-ichi Wakamatsu. "CO Observations of Luminous IR Galaxies at Intermediate Redshift." Publications of the Astronomical Society of Japan 52, no. 5 (October 1, 2000): 803–20. http://dx.doi.org/10.1093/pasj/52.5.803.

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35

Borne, K. D., H. Bushouse, L. Colina, and R. A. Lucas. "Early Results from an HST Imaging Survey of the Ultraluminous IR Galaxies." Symposium - International Astronomical Union 179 (1998): 275–77. http://dx.doi.org/10.1017/s0074180900128761.

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The intense study of interacting galaxies originated in large part with the discovery by IRAS that the most IR-luminous galaxies are nearly all products of collisions and may be the missing link in the chain of evolution from quasars to normal quiescent galaxies (Sanders et al. 1988a,b). These galaxies (with LIR > 1012L⊙) are considered to be the most strongly starbursting of all galaxies in the local universe, have a higher space density than quasars, emit >90% of their power in the IR, are rich in the raw materials of star formation, and to a large extent owe their peculiar morphologies to encounters with other galaxies. The particular importance of IR-luminous galaxies in the grand scheme of cosmology and galaxy evolution has been underscored by the luminosity function studies of Soifer et al. (1986), which indicated that most galaxies have gone through a high-IR luminosity stage. We are using the Hubble Space Telescope to survey the fine-scale features that are associated with the interaction- and activity-related processes that are at work within the Ultraluminous IR Galaxy Sample. It is widely believed that these galaxies are undergoing star formation at a prodigious rate and are abnormally dust-enshrouded. An alternative to the starburst hypothesis is that these galaxies' IR luminosity is powered by a dust-hidden quasar at its center (Sanders et al. 1988a). It is important for our understanding of the evolution of galaxies and quasars to determine which of these two hypotheses is valid, or in which objects they are separately valid.

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Gilmore, G., and K. Arnaud. "Direct IR Determination of the Stellar Luminosity Function to 0.2 M⊙ in Elliptical Galaxies." Symposium - International Astronomical Union 127 (1987): 445–46. http://dx.doi.org/10.1017/s0074180900185663.

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SummaryWe present a determination of the stellar luminosity function in luminous elliptical galaxies which includes all stars more massive than 0.15 M⊙. This limit corresponds to masses beyond the maximum in the solar neighbourhood stellar mass function, and therefore includes effectively all the luminous mass. Galaxies with X-ray evidence for current massive star formation, also show no evidence for enhanced low mass star formation in their central regions. All elliptical galaxies studied to date have stellar luminosity functions for masses above 0.15 solar masses which do not differ significantly from that in the solar neighbourhood. Elliptical galaxies have stellar bolometric mass-to-light ratios of 2.5< M/L <5.0.

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Kong, Albert, and Rosanne Di Stefano. "Ultra-luminous Supersoft X-ray Sources in Nearby Galaxies." Proceedings of the International Astronomical Union 1, S230 (August 2005): 282–86. http://dx.doi.org/10.1017/s1743921306008453.

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38

Małek, K., A. Pollo, T. T. Takeuchi, V. Buat, D. Burgarella, and M. Malkan. "Dust in FIR-bright ADF-S galaxies." Proceedings of the International Astronomical Union 10, S309 (July 2014): 325. http://dx.doi.org/10.1017/s1743921314010205.

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AbstractMultiwavelength Spectral Energy Distributions (SEDs) of far-infrared (FIR) galaxies detected in the AKARI South Ecliptic Poles Survey (ADF-S) allow to trace differences between [Ultra]-Luminous Infrared Galaxies ([U]LIRGS) and other types of star-forming galaxies (SF).

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Gao, Yu, Q. Daniel Wang, and Ted A. Markowsky. "A Galaxy Merging Sequence Traced by X-rays." Symposium - International Astronomical Union 217 (2004): 430–31. http://dx.doi.org/10.1017/s0074180900198122.

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We are studying a sample of nearly 20 nearby (cz≲13,000 km s−1) IR-luminous interacting/merging galaxies observed with the ACIS in the Chandra archive (e.g., Gao et al. 2003; Ptak et al. 2003). Most galaxies in the sample are luminous infrared galaxies (LIGs) and nearly half of them are ultraluminous infrared galaxies (ULIGs) with bolometric luminosities comparable to QSOs. Based on multiwavelength data and numerical simulations of gas-rich galaxy mergers, we have attempted to arrange them in a merger sequence perspective and compared their broadband X-ray emission here with the optical images (mostly DSS).

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Telles, Eduardo, Leda Sampson, Mauricio Tapia, Roberto Terlevich, and Daniel Kunth. "The near-infrared colours of H II galaxies." Symposium - International Astronomical Union 193 (1999): 622–23. http://dx.doi.org/10.1017/s0074180900206499.

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We present preliminary results of our near-infrared JHK images of a sample of H II galaxies observed at UKIRT. The presence of knots of enhanced emission in the near-IR may indicate the existence of luminous super star clusters which will serve to unveil the basic units which constitute the starburst phenomenon in galaxies. Based on near-IR colours we will further discuss the history of star formation in these bursting dwarf galaxies.

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41

Magdis, Georgios E., and Dimitra Rigopoulou. "Spitzer view of Lyman break galaxies." Proceedings of the International Astronomical Union 3, S245 (July 2007): 451–54. http://dx.doi.org/10.1017/s1743921308018346.

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AbstractUsing a combination of deep MID-IR observations obtained by IRAC, MIPS and IRS on board Spitzer we investigate the MID-IR properties of Lyman Break Galaxies (LBGs) at z~3, establish a better understanding of their nature and attempt a complete characterisation of the population. With deep mid-infrared and optical observations of ~1000 LBGs covered by IRAC/MIPS and from the ground respectively, we extend the spectral energy distributions (SEDs) of the LBGs to mid-infrared. Spitzer data reveal for the first time that the mid-infrared properties of the population are inhomogeneous ranging from those with marginal IRAC detections to those with bright rest-frame near-infrared colors and those detected at 24μm MIPS band revealing the newly discovered population of the Infrared Luminous Lyman Break Galaxies (ILLBGs). To investigate this diversity, we examine the photometric properties of the population and we use stellar population synthesis models to probe the stellar content of these galaxies. We find that a fraction of LBGs have very red colors and large estimated stellar masses M∗>5×1010M⊙. We discuss the link between these LBGs and submm-luminous galaxies and we report the detection of rest frame 6.2 and 7.7 μm emission features arising from Polycyclic Aromatic Hydrocarbons (PAH) in the Spitzer/IRS spectrum of an infrared-luminous Lyman break galaxy at z=3.01.

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42

Scoville, Nick. "Molecular Gas in Galactic Nuclei." Highlights of Astronomy 8 (1989): 605–7. http://dx.doi.org/10.1017/s1539299600008534.

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Recent high resolution interferometric observations of the molecular gas in luminous IR galaxies reveal extraordinary concentrations of star forming material in the central few kpc. In several of the nearest IR bright galaxies, the molecular gas in the central regions is concentrated in a bar-like distribution (IC342, NGC 6946, and NGC 253) and in NGC 1068, approximately 40% of the molecular gas is confined to two arms or a ring at approximately 1.6 kpc radius. Interferometry on the most luminous galaxies (LIR ≥ 1011L⊙) reveals that approximately half of the total interstellar matter is contained in the central kpc with mean densities of several hundred H2 cm-3. Such gas concentrations should result in the very rapid formation of stars, i.e. a central star burst yielding a massive central star cluster.

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Florez, Jonathan, Shardha Jogee, Sydney Sherman, Matthew L. Stevans, Steven L. Finkelstein, Casey Papovich, Lalitwadee Kawinwanichakij, et al. "Exploring AGN and star formation activity of massive galaxies at cosmic noon." Monthly Notices of the Royal Astronomical Society 497, no. 3 (July 29, 2020): 3273–96. http://dx.doi.org/10.1093/mnras/staa2200.

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ABSTRACT We investigate the relation between active galactic nucleus (AGN) and star formation (SF) activity at 0.5 < z < 3 by analysing 898 galaxies with X-ray luminous AGNs (LX > 1044 erg s−1) and a large comparison sample of ∼320 000 galaxies without X-ray luminous AGNs. Our samples are selected from a large (11.8 deg2) area in Stripe 82 that has multiwavelength (X-ray to far-IR) data. The enormous comoving volume (∼0.3 Gpc3) at 0.5 < z < 3 minimizes the effects of cosmic variance and captures a large number of massive galaxies (∼30 000 galaxies with M* > 1011 M⊙) and X-ray luminous AGNs. While many galaxy studies discard AGN hosts, we fit the SED of galaxies with and without X-ray luminous AGNs with Code Investigating GALaxy Emission and include AGN emission templates. We find that without this inclusion, stellar masses and star formation rates (SFRs) in AGN host galaxies can be overestimated, on average, by factors of up to ∼5 and ∼10, respectively. The average SFR of galaxies with X-ray luminous AGNs is higher by a factor of ∼3–10 compared to galaxies without X-ray luminous AGNs at fixed stellar mass and redshift, suggesting that high SFRs and high AGN X-ray luminosities may be fuelled by common mechanisms. The vast majority ($\gt 95 {{\ \rm per\ cent}}$) of galaxies with X-ray luminous AGNs at z = 0.5−3 do not show quenched SF: this suggests that if AGN feedback quenches SF, the associated quenching process takes a significant time to act and the quenched phase sets in after the highly luminous phases of AGN activity.

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Andreani, Paola. "Dust in Evolving Galaxies." Highlights of Astronomy 12 (2002): 460–63. http://dx.doi.org/10.1017/s1539299600014088.

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AbstractI will first review the observational evidence relating dust emission and the energy production in the far-IR/submm range. This latter contains crucial information on the global baryons transformation and the related stellar activity in the Universe. Present knowledge on this topic relies mainly on the far-IR local surveys of IRAS and ISO missions and on submm/mm surveys performed with SCUBA and MAMBO arrays. Further constraints are provided by the measurements of the Cosmic far-IR Background (CFIRB). Our scanty knowledge of galaxy formation and evolution is mainly caused by the difficulties of unveiling stellar activity at redshifts larger than 1 and at present we may only have detected massive objects in a transient hyper-luminous phase. We still lack an unbiased census of the much more numerous population of lower luminosity dusty objects. It will soon be possible to disclose the entire history of evolving dusty objects, and therefore of the stellar activity, selecting unbiased samples out of far-IR imaging and photometry in deep far-IR surveys.

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Hawarden, Tim G., J. H. Huang, and Q. S. Gu. "Infrared Emission from Barred Spiral Galaxies." International Astronomical Union Colloquium 157 (1996): 54–62. http://dx.doi.org/10.1017/s0252921100049411.

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AbstractAmongst relatively undisturbed spiral galaxies of type ≤ Sc barred morphology is unquestionably associated with powerful mid- and Far-IR emission. On the other hand, even amongst early type galaxies, those with LFIR/LB < 1/3 exhibit no association of high relative FIR luminosity with barred morphology, but some association of IR colors resembling those of star formation regions (SFRs). Amongst systems with LFIR/LB < 0.1 this ratio may be anti-correlated with barredness. It appears that enhanced IR emission from those galaxies whose star formation rate is currently elevated by the the bar translates them into the group with higher FIR-to-optical luminosity ratios. Depletion of extended nearnuclear gas and dust, once the bar has swept up the currently-available supplies, may reduce the fraction of the background stellar radiation field which can be converted to FIR radiation in the inner, most luminous parts of the galaxy. Thus, after the starburst has subsided, such galaxies may be less FIR-luminous than unbarred systems. Several uncertainties remain: it is still not clear whether barred morphology is a necessary condition for the generation of a starburst in an otherwise undisturbed galaxy, while evidence as to the effect of differing bar strengths is conflicting.

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Ferris, E. R., A. W. Blain, R. J. Assef, N. A. Hatch, A. Kimball, M. Kim, A. Sajina, et al. "The black hole masses of extremely luminous radio-WISE selected galaxies." Monthly Notices of the Royal Astronomical Society 502, no. 1 (January 11, 2021): 1527–48. http://dx.doi.org/10.1093/mnras/stab048.

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ABSTRACT We present near-IR photometry and spectroscopy of 30 extremely luminous radio and mid-IR-selected galaxies. With bolometric luminosities exceeding ∼1013 $\rm {L_{\odot }}$ and redshifts ranging from z = 0.880 to 2.853, we use Very Large Telescope instruments X-shooter and Infrared Spectrometer and Array Camera to investigate this unique population of galaxies. Broad multicomponent emission lines are detected in 18 galaxies and we measure the near-IR lines $\rm {H\,\rm {\beta }}$, $\rm{[O\,{\small III}]}\, \rm {\lambda }\rm {\lambda }4959,5007$, and $\rm {H\,\rm {\alpha }}$ in 6, 15, and 13 galaxies, respectively, with 10 $\rm {Ly\,\alpha }$ and 5 C iv lines additionally detected in the UVB arm. We use the broad $\rm{[O\,{\small III}]}\, \rm {\lambda }5007$ emission lines as a proxy for the bolometric active galactic nucleus luminosity, and derive lower limits to supermassive black hole masses of 107.9–109.4 M⊙ with expectations of corresponding host masses of 1010.4–1012.0 M⊙. We measure $\rm {\lambda }_{Edd}$ > 1 for eight of these sources at a 2σ significance. Near-IR photometry and SED fitting are used to compare stellar masses directly. We detect both Balmer lines in five galaxies and use these to infer a mean visual extinction of AV = 2.68 mag. Due to non-detections and uncertainties in our ${\rm H}\, \beta$ emission line measurements, we simulate a broad ${\rm H}\, \beta$ line of FWHM = 1480 $\rm {kms^{-1}}$ to estimate extinction for all sources with measured ${\rm H}\, \alpha$ emission. We then use this to infer a mean AV = 3.62 mag, demonstrating the highly obscured nature of these galaxies, with the consequence of increasing our estimates of black hole masses by a 0.5 orders of magnitude in the most extreme and obscured cases.

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Loenen, A. F., M. Spaans, W. A. Baan, and R. Meijerink. "Mechanical feedback in the molecular ISM of luminous IR galaxies." Astronomy & Astrophysics 488, no. 1 (July 17, 2008): L5—L8. http://dx.doi.org/10.1051/0004-6361:200810327.

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TORRES, DIEGO F., and EVA DOMINGO-SANTAMARÍA. "SOME COMMENTS ON THE HIGH ENERGY EMISSION FROM REGIONS OF STAR FORMATION BEYOND THE GALAXY." Modern Physics Letters A 20, no. 37 (December 7, 2005): 2827–43. http://dx.doi.org/10.1142/s0217732305018748.

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Regions that currently are or have been subject to a strong process of star formation are good candidates to be intense γ-ray and neutrino emitters. They may even perhaps be sites where ultra high energy cosmic rays are produced. Outside the Galaxy, the more powerful sites of star formation are found within very active galaxies such as starbursts (SGs) and Luminous or Ultra-Luminous Infrared Galaxies (LIRGs or ULIRGs). Some general characteristic of these objects are herein reviewed from the point of view of their possible status as high energy emitters. Revised estimations of the high energy gamma-ray yield of Arp 220 are presented.

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Willman, Beth. "In Pursuit of the Least Luminous Galaxies." Advances in Astronomy 2010 (2010): 1–11. http://dx.doi.org/10.1155/2010/285454.

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The dwarf galaxy companions to the Milky Way are unique cosmological laboratories. With luminosities as low as10−7LMW, they inhabit the lowest mass dark matter halos known to host stars and are presently the most direct tracers of the distribution, mass spectrum, and clustering scale of dark matter. Their resolved stellar populations also facilitate detailed studies of their history and mass content. To fully exploit this potential requires a well-defined census of virtually invisible galaxies to the faintest possible limits and to the largest possible distances. I review the past and present impacts of survey astronomy on the census of Milky Way dwarf galaxy companions and discuss the future of finding ultra-faint dwarf galaxies around the Milky Way and beyond in wide-field survey data.

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Kim, Seong Jin. "Mid-infrared PAH emission from star-forming galaxies selected at 250 μm." Proceedings of the International Astronomical Union 15, S341 (November 2019): 281–82. http://dx.doi.org/10.1017/s1743921319002928.

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AbstractThe infrared (IR) galaxies detected at Herschel/SPIRE 250 μm band over the AKARI’s NEP-Wide field are various types of dusty star-forming (SF) galaxies ranging from quiescent to starbursts, having mid-IR polycyclic aromatic hydrocarbon (PAH) features near 8 μm. The measurements of the 8 μm luminosity (L8μm) along with the total infrared luminosity (LIR) based on the physical modeling of SEDs a take unique advantage of the continuous near- to mid-IR coverage, far-IR data points, and spectroscopically determined accurate redshifts. Our sample shows shortage of 8 μm luminosity compared to the total IR luminosity. This deficit gets severe in more luminous IR galaxies, suggesting PAH molecules in these galaxies are destroyed by a strong radiation field from SF regions, or the existence of a unexpectedly large amount of cold dust in the ISM that contributes to LIR.

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