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Journal articles on the topic 'K luminosity'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Wagner, S. J., and M. W. Kümmel. "The K-Band Luminosity Function." Symposium - International Astronomical Union 171 (1996): 465. http://dx.doi.org/10.1017/s0074180900233834.

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Investigations of broad band energy distributions of specific classes of sources requires homogeneous samples of a sufficiently large number of objects. Deep and homogeneous surveys in those energy ranges which are accessible to satellites only are rare. One such a field in the north ecliptic pole (NEP). The ROSAT and IRAS whole sky surveys and deep additional observations by other satellites make the NEP the region of the deepest mid-IR and X-ray observations. We performed complete surveys in three optical/IR colors at 460nm, 700nm, and 2.1 μm (B, R, and K′) within a one square degree field around the NEP. Limiting magnitudes in the three bands are 23, 24, and 19, respectively. The optical bands are observed with sufficient spatial sampling to classify extended and point sources. Down to levels which still correspond to high completeness limits we detect 80.000, 240.000 and 25.000 sources in B, R, and K′, respectively.

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2

Gardner, J. P., R. M. Sharples, C. S. Frenk, and B. E. Carrasco. "The K-Band Luminosity Function of Galaxies." Symposium - International Astronomical Union 179 (1998): 278–80. http://dx.doi.org/10.1017/s0074180900128773.

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The luminosity function of galaxies is central to many problems in cosmology, including the interpretation of faint number counts. The near-infrared provides several advantages over the optical for statistical studies of galaxies, including smooth and well-understood K-corrections and expected luminosity evolution. The K–band is dominated by near-solar mass stars which make up the bulk of the galaxy. The absolute K magnitude is a measure of the visible mass in a galaxy, and thus the K–band luminosity function is an observational counterpart of the mass function of galaxies.

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3

Baker, A. C., and P. C. Hewett. "K-Correction Biases and the Quasar Luminosity Function." Symposium - International Astronomical Union 159 (1994): 498. http://dx.doi.org/10.1017/s0074180900176715.

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By characterising the range of quasar UV-optical spectral indices and any correlation with it e.g. luminosity or line parameters, we hope to remove one more bias from the quasar luminosity function (QLF).

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4

Deng, Xin-Fa, Xiao-Qing Wen, Yong Xin, Xiao-Ping Qi, and Ying-Ping Ding. "K-band luminosity–density relation at fixed parameters or for different galaxy families." Open Physics 18, no. 1 (July 9, 2020): 290–301. http://dx.doi.org/10.1515/phys-2020-0016.

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AbstractUsing the apparent magnitude-limited Main galaxy sample of the Sloan Digital Sky Survey Data Release 10, we examine the K-band luminosity–density relation at fixed parameters or for different galaxy families. It is found that the limiting or fixing galaxy properties, such as galaxy morphology, stellar mass, and color, exert substantial influence on the environmental dependence of the K-band luminosity of galaxies, which suggests that the K-band luminosity–density relation is likely attributable to the relation between these galaxy properties and density.

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5

Gyulbudaghian, A. L., N. Baloian, and I. A. Sanchez. "Color-color diagrams in near infrared: (J-H)/(H-K). II." Communications of the Byurakan Astrophysical Observatory 2, no. 1 (2018): 21–26. http://dx.doi.org/10.52526/25792776-2018.2.1-21.

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In the paper the color-color diagrams (J-H)/(H-K) for all stars with visible magnitudes B<11m (for which in the existing catalogs the magnitudes of J, H, K, and also their spectral types and luminosity classes are given) are presented. In the preceding paper the data for luminosity classes I, Ia, Ib, II and III were given. In this paper the data on luminosity classes IV (sub giants) and V (main sequence stars) are given. Among the diagrams of luminosity classes the most interesting are the diagrams for GII and GIV stars, each of these diagrams have two centers of concentrations. For stars of spectral class M the minimal amount of stars is at luminosity class IV, the maximal –at class III, which is not so for other spectral classes: for other classes the maximal amount is at class V. There is a tendency (seen in all diagrams)of increasing of the values of J-H and H-K along the sequence O-B-A-F-G-K-M.

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6

Loveday, Jon. "Optical and Near-IR Field Luminosity Functions." International Astronomical Union Colloquium 171 (1999): 68–75. http://dx.doi.org/10.1017/s0252921100054130.

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AbstractWe present preliminary measurements of the bJ and K-band luminosity functions (LFs) of field galaxies obtained from optical and K-band imaging of a sample of galaxies selected from the Stromlo-APM Redshift Survey. The bJ LF is consistent with that previously published from photographic data. The K-band LF has been estimated over a range of 12 magnitudes and is reasonably well fit by a Schechter function with faint-end slope α = −1.2.

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7

Brainerd, Tereasa G. "K-band Luminosity Functions of IllustrisTNG300-1 Galaxies." Research Notes of the AAS 5, no. 10 (October 8, 2021): 224. http://dx.doi.org/10.3847/2515-5172/ac2d36.

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8

Alves, David R. "K‐Band Calibration of the Red Clump Luminosity." Astrophysical Journal 539, no. 2 (August 20, 2000): 732–41. http://dx.doi.org/10.1086/309278.

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9

Brunello, A., P. Saracco, B. Garilli, D. Maccagni, and G. Chincarini. "Multicolor Luminosity Function of Field Galaxies." Symposium - International Astronomical Union 183 (1999): 156. http://dx.doi.org/10.1017/s007418090013236x.

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The aim of this programme is to determine the luminosity function of field galaxies in different bands for a unique sample. From the ESP [1] redshift survey of 3344 bj ≤ 19.4 galaxies, we have extracted a fair subsample and obtained multicolor photometry for 354 (11%) galaxies in the V, R (Johnson) and i (Gunn) filters and for 148 (4%) in the K′ band. Errors on the total magnitudes are smaller than 0.1 in all bands. In order to obtain absolute magnitudes, we applied k-corrections [2] after deriving a rough morphological classification based on color information. Here we present a by product of this programme: the determination of the color-luminosity relationship. The figure shows how the rest-frame Bj-K' color is strongly related to the absolute i magnitude while such correlation is not present using optical colors. If we assume Mi is a good mass tracer, the figure indicates that bluer galaxies are the less massive ones.

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10

Loveday, J. "The K-band luminosity function of nearby field galaxies." Monthly Notices of the Royal Astronomical Society 312, no. 3 (March 1, 2000): 557–66. http://dx.doi.org/10.1046/j.1365-8711.2000.03179.x.

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11

Petrosian, Vahé. "The Evolution and Luminosity Function of Quasars." Symposium - International Astronomical Union 194 (1999): 105–12. http://dx.doi.org/10.1017/s0074180900161832.

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I report results from analysis of data from several quasar samples (Durham/AAT, LBQS, HBQS and EQS) on the density and the luminosity evolution of quasars. We have used new statistical methods whereby we combine these different samples with varying selection criteria and multiple truncations. With these methods the luminosity evolution can be found through an investigation of the correlation of the bivariate distribution of luminosities and redshifts. Of the two most commonly used models for luminosity evolution, L = ekt(z) and L = (1 + z)k', we find that the second form, with k' = 2.58 (one σ range [2.14,2.91]), gives a better description of the data at all luminosities. Using this form of luminosity evolution we determine a global luminosity function and the evolution of the co-moving density for the two classes of cosmological models. We find a gradual increase of the co-moving density up to z ˜ 2, at which point the density peaks and begins to decrease rapidly. This is in agreement with results from high redshift surveys and in disagreement with the pure luminosity evolution (i.e. constant co-moving density) model. We find that the local luminosity function exhibits the usual double power law behavior. The luminosity density is found to increase rapidly at low redshift and to reach a peak at around z ≍ 2. This result is compared with those from high redshift surveys and with the evolution of the star formation rate.

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12

Fedotovich, G. V., R. R. Akhmetshin, A. N. Amirkhanov, A. V. Anisenkov, V. M. Aulchenko, V. S. Banzarov, N. S. Bashtovoy, et al. "Study of the processes e+e-→ K+K− + nπ (n = 1,2,3) with the CMD-3 detector at the VEPP-2000 electron-positron collider." EPJ Web of Conferences 218 (2019): 02008. http://dx.doi.org/10.1051/epjconf/201921802008.

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The data sample collected in 2011-2013 at the c.m.s. energies between 0.32-2 GeV with the CMD-3 detector operating at the VEPP-2000 e+e− collider is analzed. The collected data corresponds to an integrated luminosity about ∼ 60pb−1. The techniques for determination of the integrated luminosity for each energy setting is described. Some preliminary results of the study of the processes e+e−→ K+ K− + nπ (n = 1,2,3) with two charged kaons in the final state are presented. These processes have several intermediate states, which are important to correctly descript the angular distributions of final particles and the cross sections dependence on the energy.

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13

Laney, C. D., and R. S. Stobie. "Cepheid period-luminosity relations in K, H, J and V." Monthly Notices of the Royal Astronomical Society 266, no. 2 (January 15, 1994): 441–54. http://dx.doi.org/10.1093/mnras/266.2.441.

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14

Ting-Gao, Yang, Shu Cheng-Gang, Fu Cheng-Qi, Jiang Dong-Rong, and Peng Qiu-He. "The Luminosity Function of the Main Sequence Stars in the Solar Neighborhood." Highlights of Astronomy 11, no. 1 (1998): 400. http://dx.doi.org/10.1017/s153929960002150x.

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The Third Catalogue of Nearby Stars (CNS3) was analyzed. A study of the stellar luminosity function in the solar neighborhood with CNS3 was described. The luminosity function for main sequence stars derived from CNS3 was compared with that from CNS2 and that based on the method of photometric parallaxes. The results from CNS3 for stars with Mv <15.5 were well defined. Luminosity functions for the giants and A, F, G, K and M type main sequence stars are also given, based on CNS3.

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15

Keenan, Ryan C., Amy J. Barger, and Lennox L. Cowie. "Local Large-Scale Structure and the Assumption of Homogeneity." Proceedings of the International Astronomical Union 11, S308 (June 2014): 295–98. http://dx.doi.org/10.1017/s1743921316010024.

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AbstractOur recent estimates of galaxy counts and the luminosity density in the near-infrared (Keenan et al. 2010, 2012) indicated that the local universe may be under-dense on radial scales of several hundred megaparsecs. Such a large-scale local under-density could introduce significant biases in the measurement and interpretation of cosmological observables, such as the inferred effects of dark energy on the rate of expansion. In Keenan et al. (2013), we measured the K-band luminosity density as a function of distance from us to test for such a local under-density. We made this measurement over the redshift range 0.01 < z < 0.2 (radial distances D ~ 50 - 800 h70−1 Mpc). We found that the shape of the K-band luminosity function is relatively constant as a function of distance and environment. We derive a local (z < 0.07, D < 300 h70−1 Mpc) K-band luminosity density that agrees well with previously published studies. At z > 0.07, we measure an increasing luminosity density that by z ~ 0.1 rises to a value of ~ 1.5 times higher than that measured locally. This implies that the stellar mass density follows a similar trend. Assuming that the underlying dark matter distribution is traced by this luminous matter, this suggests that the local mass density may be lower than the global mass density of the universe at an amplitude and on a scale that is sufficient to introduce significant biases into the measurement of basic cosmological observables. At least one study has shown that an under-density of roughly this amplitude and scale could resolve the apparent tension between direct local measurements of the Hubble constant and those inferred by Planck team. Other theoretical studies have concluded that such an under-density could account for what looks like an accelerating expansion, even when no dark energy is present.

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16

Khata, Dhrimadri, Soumen Mondal, Ramkrishna Das, Supriyo Ghosh, and Samrat Ghosh. "Understanding the physical properties of young M dwarfs: NIR spectroscopic studies." Monthly Notices of the Royal Astronomical Society 493, no. 3 (March 18, 2020): 4533–50. http://dx.doi.org/10.1093/mnras/staa427.

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ABSTRACT We present here medium resolution (λ/Δλ ∼ 1200) H- and K-band spectra of M-type dwarf stars covering the wavelength ranges 1.50–1.80 μm and 1.95–2.45 μm. The sample includes 53 dwarf stars (M0V–M7V) from new observations using the TIFR Near-Infrared Spectrometer and Imager instrument on the 2-m Himalayan Chandra Telescope. Using interferometrically measured effective temperature (Teff), radius and luminosity of nearby bright calibrator stars, we have created new empirical relationships among those fundamental parameters and spectral indices. The equivalent widths of H-band spectral features like Mg (1.57 μm), Al (1.67 μm) and Mg (1.71 μm), and the H2O–H index are found to be good indicators of Teff, radius and luminosity and we establish linear functions using these features relating to those stellar parameters. The root-mean-squared error of our best fits are 102 K, 0.027$\, \mathrm{R}_{\odot }$ and 0.12 dex respectively. Using spectral-type standards along with known parallaxes, we calibrate both H- and K-band H2O indices as a tracer of spectral type and absolute Ks magnitude. Metallicities of M-dwarf samples are estimated using the K-band calibration relationships. The masses of M dwarfs could be determined using the luminosity ($L/{\rm L_\odot }$) and we establish a new empirical relation for this. We also compare and contrast our results with other similar work from the literature.

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17

Comerón, F., and F. Figueras. "The K supergiant runaway star HD 137071." Astronomy & Astrophysics 638 (June 2020): A90. http://dx.doi.org/10.1051/0004-6361/202038136.

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Context. Extensive work exists on runaway massive stars with peculiar motions that are much higher than those typical of the extreme Population I to which they belong. Work on runaways has focused almost exclusively on O and B stars, most of which undergo a red supergiant phase before ending their lives as supernovae. Very few examples are known of red supergiant runaways, all of which descend from the more massive O-type precursors, but none from the lower mass B-type precursors, although runaway statistics of B-type stars suggest that K-type runaways must be relatively numerous. Aims. We study HD 137071, a star that has so far been considered to be a normal K-type red giant. Its parallax measured by Gaia and the derived luminosity suggest that it is a supergiant, whereas its derived distance to the Galactic plane and its spatial velocity of 54.1 km s−1 with respect to the local standard of rest suggest that it is also a runaway star. However, intrinsic limitations in determining the trigonometric parallaxes of cool supergiants, even in the Gaia era, require accurate spectral classifications for confirmation. Methods. We present visible spectroscopy obtained with the 2.2m telescope at Calar Alto Observatory and compare it with the spectra of MK standard stars to produce an accurate spectral classification, including the determination of its luminosity class. We complement this information with astrometric data from the Gaia DR2 catalog. Results. We reliably classify HD 137071 as a K4II star and establish its membership to the extreme Population I. This agrees with the luminosity derived using the Gaia DR2 parallax measurement. Kinematical data from the Gaia DR2 catalog confirm its high spatial velocity and runaway nature. By combining the spectral classification with astrometric information, recent Galactic potential models, and evolutionary models for high-mass stars, we trace the motion of HD 137071 back to the proximities of the Galactic plane and speculate which of the two proposed mechanisms for the production of runaway stars may be responsible for the high velocity of HD 137071. The available data favor the formation of HD 137071 in a massive binary system where the more massive companion underwent a supernova explosion about 32 Myr ago.

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18

Chekhonadskikh, F. A. "Lines of iron as luminosity indicators for F-, G-, K-supergiants." Astronomical School’s Report 6, no. 2 (2009): 151–54. http://dx.doi.org/10.18372/2411-6602.06.2151.

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19

Bell, R. A., and M. J. Tripicco. "Molecular equilibria and the luminosity classification of G and K stars." Astronomical Journal 102 (August 1991): 777. http://dx.doi.org/10.1086/115909.

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20

Bono, G., F. Caputo, V. Castellani, M. Marconi, and J. Storm. "Theoretical insights into the RR Lyrae K-band period--luminosity relation." Monthly Notices of the Royal Astronomical Society 326, no. 3 (September 21, 2001): 1183–90. http://dx.doi.org/10.1046/j.1365-8711.2001.04655.x.

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21

Jennings, Jeff, and Emily M. Levesque. "HαAS A LUMINOSITY CLASS DIAGNOSTIC FOR K- AND M-TYPE STARS." Astrophysical Journal 821, no. 2 (April 22, 2016): 131. http://dx.doi.org/10.3847/0004-637x/821/2/131.

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22

Nishiura, S., T. Murayama, Y. Taniguchi, Y. Sato, and D. B. Sanders. "A K-Band Luminosity Function of Hickson Compact Groups of Galaxies." Symposium - International Astronomical Union 186 (1999): 415. http://dx.doi.org/10.1017/s0074180900113294.

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23

Gardner, J. P. "Galaxy Evolution from Deep Galaxy Counts." Symposium - International Astronomical Union 164 (1995): 311–19. http://dx.doi.org/10.1017/s007418090010871x.

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We present deep galaxy number counts and colours of K – band selected galaxy surveys. We argue that primeval galaxies are present within the survey data, but have remained unidentified. There are few objects with the colours of an L∗ elliptical galaxy at a redshift of z ≈ 1, in contradiction to standard luminosity evolution models. We present K – band photometry of the objects in a spectroscopic redshift survey selected at 21 < B < 22.5. The absolute K magnitudes of the galaxies are consistent with the no-evolution or pure luminosity evolution models. The excess faint blue galaxies seen in the B – band number counts at intermediate magnitudes are a result of a low normalization, and do not dominate the population until B ≈ 25. Extreme merging or excess dwarf models are not needed at z < 1.

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24

Makishima, K., N. Iyomoto, Y. Ishisaki, and Y. Terashima. "X-Ray Observations of Low-Luminosity Active Galactic Nuclei." International Astronomical Union Colloquium 159 (1997): 52–53. http://dx.doi.org/10.1017/s0252921100039610.

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AbstractThrough X-ray observations with ASCA, low-luminosity active galactic nuclei have been found in at least seven near-by spiral galaxies. Some of them exhibit very intense, and possibly broad, Fe-K emission lines. Their time variability is relatively insignificant, in contrast to lowluminosity Seyfert galaxies.

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25

Blundell, K. M., S. Rawlings, S. A. Eales, and M. Lacy. "New Results from Complete Samples of Faint Radio Galaxies and Quasars." Symposium - International Astronomical Union 175 (1996): 567–68. http://dx.doi.org/10.1017/s0074180900081870.

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In any flux-limited sample a tight correlation of luminosity (P) and redshift (z) is inevitable. It is therefore necessary to obtain complete samples at lower and lower flux-limits in order to have adequate coverage of the P–z plane, essential if we are to decouple the trends in epoch from trends in luminosity. This we have done for a number of flux-limits — giving coverage of the P–z plane seen in Fig. 1. Our redshift information is spectroscopic; the results of Eales et al (in prep.), namely the increased scatter in theK-z plot for samples lower in luminosity than 3C, strongly warn us against using redshifts estimated from K-magnitudes.

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26

Zaninetti, L. "Semi-analytical formulas for the fundamental parameters of galactic early B supergiants." Serbian Astronomical Journal, no. 179 (2009): 69–74. http://dx.doi.org/10.2298/saj0979069z.

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The publication of new tables of calibration of some fundamental parameters of Galactic B0-B5 supergiants in the two classes Ia and Ib allows to particularize the eight parameters conjecture that model five fundamental parameters. The numerical expressions for visual magnitude, radius, mass, luminosity and surface gravity are derived for supergiants in the range of temperature between 29700 K and 15200 K. The availability of accurate tables of calibration allows us to estimate the efficiency of the derived formulas in reproducing the observed values. The average efficiency of the new formulas, expressed in percent, is 94 for the visual magnitude, 81 for the mass, 96 for the radius, 99 for the logarithm of the luminosity and 97 for the logarithm of the surface gravity.

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27

Matute, Israel, Fabio La Franca, Carlotta Gruppioni, Francesca Pozzi, and Carlo Lari. "Unveiling the Evolution of Type I AGNs in the IR (15μm) — As Seen by ISO in the ELAIS-S1 Region." International Astronomical Union Colloquium 184 (2002): 167–72. http://dx.doi.org/10.1017/s0252921100030645.

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AbstractWe present the first estimate of the evolution of type 1 AGNs in the IR (15 μm) obtained from the ELAIS survey in the S1 region. We find that the luminosity function (LF) of Type 1 AGNs at 15μm is fairly well represented by a double power-law function with a bright slope of 2.9 and a faint slope of 1.1. There is evidence for significant cosmological evolution according to a pure luminosity evolution model L15(z)α(l+z)k, with in a (Ωm,ΩΛ)=(1.0,0.0) cosmology. This evolution is similar to what is observed at other wavebands. From the luminosity function and its evolution, we estimate a contribution of ~ 2% from Type 1 AGN to the total Cosmic Infrared Background (CIRB) at 15 μm.

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28

Vaduvescu, O., V. Petropoulou, D. Reverte, and V. Pinter. "Studying star forming dwarf galaxies in Abell 779, Abell 1367, Coma, and Hercules clusters." Astronomy & Astrophysics 616 (August 2018): A165. http://dx.doi.org/10.1051/0004-6361/201833113.

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Context. We continue to study star formation in dwarf galaxies located in nearby clusters. Aims. Known physical and chemical relations outlining the formation and evolution of dwarfs is compared in different environments, including the Local Volume (LV) and some nearby clusters studied previously. Methods. We used the TNG telescope for four nights in 2010 to acquire deep near-infrared imaging in K′ of 45 star forming dwarf galaxies located in the Abell 779, Abell 1367, Abell 1656 (Coma), and Abell 2151 (Hercules) clusters. Results. Surface photometry was approached based on past experience by using the sech law to account for the outer old stellar contribution plus a Gaussian component to model the inner starburst, proving the blue compact dwarf (BCD) classification of most targets. Sech central surface brightness, semimajor axis, sech, and total apparent magnitude were measured, allowing to estimate size, absolute luminosity and mass for all targets. Conclusions. The physical correlations between size, central brightness, and NIR luminosity appear to hold, but previously known linear fits break above MSK = − 19 for Abell 779, Abell 1367 and especially for Hercules, while the dwarf fundamental plane (FP) is probed by only half cluster members, suggesting harassment by the denser cluster environments. Nevertheless, the chemical relations between the oxygen abundance, luminosity, gas mass, baryonic mass, and gas fraction in a closed box model are probed by most members of the four studied clusters, and the starburst grows linearly with the K′ luminosity.

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29

Terashima, Y., H. Kunieda, P. J. Serlemitsos, and A. Ptak. "X-Ray Properties of LINERs and Low Luminosity Seyfert Galaxies Observed with ASCA." Symposium - International Astronomical Union 188 (1998): 444–45. http://dx.doi.org/10.1017/s0074180900115943.

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We present ASCA spectra of low luminosity AGNs with X-ray luminosities of 1040-41 ergs s−1. Their X-ray continua are very similar to Seyfert galaxies. Although iron K emissin centered at 6.4 keV or 6.7 keV is detected from a few objects, iron K emission is weak on average. Possible reasons for variety of iron line properties are discussed.

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30

Dumont, Antoine, Anil C. Seth, Jay Strader, Jenny E. Greene, Leonard Burtscher, and Nadine Neumayer. "Surprisingly Strong K-band Emission Found in Low-luminosity Active Galactic Nuclei." Astrophysical Journal 888, no. 1 (December 30, 2019): 19. http://dx.doi.org/10.3847/1538-4357/ab5798.

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31

Lin, Yen-Ting, Joseph J. Mohr, Anthony H. Gonzalez, and S. Adam Stanford. "Evolution of the K -Band Galaxy Cluster Luminosity Function and Scaling Relations." Astrophysical Journal 650, no. 2 (October 4, 2006): L99—L102. http://dx.doi.org/10.1086/508940.

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32

Blum, R. D., K. Sellgren, and D. L. Depoy. "JHKL Photometry and the K-Band Luminosity Function at the Galactic Center." Astrophysical Journal 470 (October 1996): 864. http://dx.doi.org/10.1086/177917.

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33

Wills, Beverley J. "The Infrared Spectra of Quasars - A Luminosity Dependence." Symposium - International Astronomical Union 124 (1987): 665–68. http://dx.doi.org/10.1017/s0074180900159728.

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The IR-optical-UV continua of quasars are often represented by two components: (i) a flat spectrum component dominating in the optical-UV (the “Big Bump”) and sometimes attributed to thermal radiation from an accretion disk with temperatures of about 20000 to 40000 K - we will call it the “disk” component - and (ii) a near IR component characterized by a steep rise, α ∼ 1 for λ > 1 μm, often thought to be a synchrotron spectrum - an extrapolation of the cm or mm wavelength radio spectrum - although some have preferred an explanation in terms of thermal re-radiation of the ionizing continuum by hot dust (e.g., Hyland and Allen 1982, Neugebauer et al. 1979).

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Mosconi, Mirta, Patricia Tissera, and Diego Garcia Lambas. "Evolution of Galaxy Luminosity in the CDM Model." Symposium - International Astronomical Union 168 (1996): 503–4. http://dx.doi.org/10.1017/s0074180900110502.

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we analyze the evolution of the luminosity function of galaxies using the CDM model in numerical simulations. There is an observational excess in the number counts of galaxies per square degree in the blur band Nb(i.e. APM, Maddoxet al.1990). Several authors have tried to reproduce it trying to fit the observations. Our model assumes an instantaneous star formation rate (SFR) proportional to a power of the local density. A ‘single star burst’ is produced each time step and we follow the evolution of the luminosity and colour of each ‘stellar group’. The galaxies are identified with a density criterium. We compute U,V,B,K colours and Nband our results agree quite well with observations.

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35

Nemec, James M., and Thomas E. Lutz. "Period-Luminosity-Metal Abundance Relations for Population II Variable Stars." International Astronomical Union Colloquium 139 (1993): 31–52. http://dx.doi.org/10.1017/s0252921100116896.

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AbstractNew period-luminosity-metallicity (P-L-[Fe/H]) relationships for Pop. II Cepheids, RR Lyrae stars, anomalous Cepheids and SX Phe (variable-blue straggler) stars are presented. These were computed by fitting regression lines to observed pulsation periods and mean B, V, K magnitudes for over 1200 stars in ∼40 stellar systems. The stars were assumed to be pulsating in either the fundamental (F) or first-overtone (H) modes (excluding double-mode and other multi-periodic variables). Eight P-L-[Fe/H] relationships (one for each of the two pulsation modes for the four kinds of stars) were simultaneously fitted for each filter. After accounting for the metal abundance differences, the slopes of the P-L relations were tested for departures from equality. The results are consistent with the assumption that, for each kind of star, the relations for the F and H stars are vertically offset, with a family of lines corresponding to the different metallicities. In the case of the globular cluster Cepheids, the available B, V data support Arp's 1955 contention that the Cepheids are oscillating in the F and H modes; moreover, the majority of the short-period Cepheids (BL Her stars) appear to be first-overtone pulsators, while most of the Cepheids with periods between 10 and 30 days (W Vir stars) appear to be fundamental-mode pulsators. For the RR Lyrae stars, the slopes of the P-L-[Fe/H] relations in B, V and K show a clear trend with filter type, namely, the absolute values of the slopes increase from B to K. Finally, for the SX Phe stars the differences between the P-L-[Fe/H] relations in B and V for the F and H stars are found to be consistent with the known period-ratio for the double-mode star SX Phe.

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Kümmel, M. W., and S. J. Wagner. "Identifications of Faint IRAS Sources." Symposium - International Astronomical Union 171 (1996): 402. http://dx.doi.org/10.1017/s0074180900233214.

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From overlapping scans in the IRAS all-sky survey and additional pointed observations the deepest far infrared survey before ISO exists in the region around the North Ecliptic Pole (NEP) (Hacking P. and Houck J.R., ApJS 63 p. 311). This survey contains detections up to 10 and fluxes up to 100 times fainter than the IRAS survey. In the central square degree around the NEP we combine the far IR-survey with deep radio data at 151 MHz and 1.5 GHz (Visser, A.E. et al., A&AS 110 p. 419, Kollgaard, R.I. et al., ApJS 93 p. 145) and own observation at 2.2μm (K′) and 435nm (B). The error circle around the IRAS source was chosen to include the true source with 85% probability (1.4 sigma). For 29 of the 32 IRAS sources we found at least one possible counterpart. Ten of the objects have multiple (up to four) counterparts in K′. Four of the IRAS sources have counterparts in the 1.5 GHz survey. The higher accuracy of the radio position (∼ 1″) allowed an unambiguous identification of the K′ counterpart. None of the IRAS sources could be found in the 151 MHz survey. The broad band spectra of the three galaxies with measured radio flux exhibit maximum emission between the radio band and 100μm which corresponds to emission by cool dust (< 50 K). Contrary to the infrared luminosity functions at 12μm and 60μm which show power laws, the K′ luminosity function is bimodal. The brightest K′ objects are all point sources. Due to the small number statistics the power law indices of the luminosity functions can not be distinguished. We find a linear relationship between the K′ flux and the flux at 60μm and 12μm over at least one decade. The large deviations by individual sources make an identification of the correct counterpart through this relation impossible. The spectral energy distributions of unambiguously identified sources span only one decade in energy (vSv), i.e. they have flat energy distributions. This suggests an identification of K′ objects with flat energy distribution in case of multiple counterparts.

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37

Page, M. J., T. Dwelly, I. McHardy, N. Seymour, K. O. Mason, M. Sharma, J. A. Kennea, et al. "The ultraviolet luminosity function of star-forming galaxies between redshifts of 0.6 and 1.2." Monthly Notices of the Royal Astronomical Society 506, no. 1 (June 14, 2021): 473–87. http://dx.doi.org/10.1093/mnras/stab1638.

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ABSTRACT We use ultraviolet (UV) imaging taken with the XMM–Newton Optical Monitor telescope (XMM-OM), covering 280 arcmin2 in the UVW1 band (λeff = 2910 Å) to measure rest-frame UV 1500-Å luminosity functions of galaxies with redshifts z between 0.6 and 1.2. The XMM-OM data are supplemented by a large body of optical and infrared imaging to provide photometric redshifts. The XMM-OM data have a significantly narrower point spread function (resulting in less source confusion) and simpler K-correction than the GALEX data previously employed in this redshift range. UV-bright active galactic nuclei are excluded to ensure that the luminosity functions relate directly to the star-forming galaxy population. Binned luminosity functions and parametric Schechter-function fits are derived in two redshift intervals: 0.6 < z < 0.8 and 0.8 < z < 1.2. We find that the luminosity function evolves such that the characteristic absolute magnitude M* is brighter for 0.8 < z < 1.2 than for 0.6 < z < 0.8.

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38

Andredakis, Y., R. Peletier, and M. Balcells. "The Shape of the Luminosity Profiles of Bulges." International Astronomical Union Colloquium 157 (1996): 86–87. http://dx.doi.org/10.1017/s0252921100049472.

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AbstractWe extract the bulge light profiles of a sample of early type spirals, using K-band photometry and a new 2-dimensional decomposition method that does not assume a priori any surface brightness laws. We find that the shape of the light profile shows a good correlation with the morphological type of the galaxy, in the sense that the profiles tend to fall off more steeply at large radii for the later types. This trend shows that the formation of or interaction with the disk has probably affected the density distribution of the bulge. The fact that the transition in shape is continuous might also imply that most of the bulges of late type spirals were not formed by different mechanisms than the ones of early types.

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39

Gnedin, Yu N. "Chromospheres, activity and magnetic fields." Symposium - International Astronomical Union 189 (1997): 245–52. http://dx.doi.org/10.1017/s0074180900116754.

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This brief review presents the current state of observations of stellar activity effects including the fluxes of chromospheric emission lines: CaII H+K, MgII h+k, SiII 1812 Å multiplet, CIV, as well as radio and X-ray fluxes versus B-V colours and luminosity classes, rotation periods, Rossby number and especially versus the mean magnetic flux density 〈fB〉. Results of stellar magnetic field measurements are presented.

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40

Wing, Robert F. "K–Type Supergiants in the Large Magellanic Cloud." Proceedings of the International Astronomical Union 14, S343 (August 2018): 544–45. http://dx.doi.org/10.1017/s1743921318006993.

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AbstractTwo-dimensional spectral classifications, on a narrow-band photometric system that measures near-infrared bands of TiO and CN, are being obtained for several hundred previously unclassified “suspected late-type supergiants” in the Large Magellanic Cloud. The objective is to identify supergiants of spectral type K, which are known to be plentiful in the Small Magellanic Cloud but were thought to be rare in the LMC. In the fields examined to date, 35 % of the targets are found to be K-type supergiants, while 25 % are early-M supergiants and 40 % are foreground stars of lower luminosity.

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41

Liu, T., and K. A. Janes. "Infrared Period-Luminosity Relations of RR Lyraes in M5 and Ml5." International Astronomical Union Colloquium 139 (1993): 30. http://dx.doi.org/10.1017/s0252921100116884.

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AbstractWe have carried out K band photometric observations of RR Lyrae stars in two globular clusters which both have large populations of RR Lyraes but different characteristics: the moderately metal-rich cluster M5 ([Fe/H] = –1.40) and the metal-poor one M15 ([Fe/H] = –2.15). The purpose is to accurately calibrate the linear relationship between RR Lyrae infrared (K) absolute magnitudes and their periods that has been confirmed by recent Baade-Wesselink type studies of RR Lyraes and IR photometry of cluster variables. A total of 47 RR Lyraes in M15 was observed and each has more than 8 measures on the average, which allows the accurate determination of a mean K magnitude for each star. In M5 44 stars have been observed with each RR Lyrae having 4 measurements. Our preliminary results show that the RR Lyrae infrared period-luminosity relations for the two clusters have roughly the same slope, despite the fact that they have a large metallicity difference. This suggests that the metallicity effect on the (MK)-log P relation is indeed small as one would expect. The M5 and M15 RR Lyrae IR photometry gives a reliable determination for the slope of the infrared period-luminosity relation because of the large number of stars measured. A well-calibrated (MK)-log P relation will be very useful in distance determinations to heavily reddened star regions such as the Galactic center and globular clusters in the Galactic bulge.

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42

Haller, Joseph W., and Marcia J. Rieke. "A Search for Variable Stars at the Galactic Center." Symposium - International Astronomical Union 136 (1989): 487–92. http://dx.doi.org/10.1017/s0074180900186942.

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A study of the Galactic Center stellar population is continuing with a sensitive 2μm CCD camera. Using a 64 × 64 detector array, background limited images are recorded with modest amounts of observing time (tobs ≈ 20 sec to reach K=13). Magnitudes have been extracted using DAOPHOT from repeated imaging of the central 5′ × 5′ to search among approximately 1500 stars for long period variables (LPV's, P > 200d), particularily Miras. Miras have a well defined period-luminosity relationship as well as one in period-mass. This program investigates the nature of highly luminous stars at the Galactic Center. Presently 12 variables have been found and have several characteristics consistent with Miras. They have a maximum bolometric luminosity of −4.4 mag, which supports the case that high luminosity stars in the central 6 pc are young supergiants.

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de Oliveira, Claudia Mendes, Sergio Torres-Flores, Philippe Amram, Henri Plana, and Benoit Epinat. "3D Studies of Galaxies in Compact Groups." Proceedings of the International Astronomical Union 10, S309 (July 2014): 175–77. http://dx.doi.org/10.1017/s1743921314009612.

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AbstractFabry-Perot data of compact group galaxies have been used to show that the Tully-Fisher relation in any photometric band, for galaxies with vmax > 100 km/s, is very similar to that for galaxies in other less dense environments. In the low-luminosity end, however, a few compact group galaxies fall above the relation apparently because they are too bright for their mass. Here we show that if the mass is properly computed from spectral energy distribution fitting or mass modelling, for the low-luminosity galaxies, their positions in the stellar-mass or baryonic Tully-Fisher relation are what is expected for a normal Tully-Fisher relation and the outlying positions observed in the B and K Tully-Fisher relation could be explained by brightening of the low-luminosity interacting galaxies due to strong star formation or AGN activity.

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44

Gómez, A. E., X. Luri, M. O. Mennessier, J. Torra, F. Figueras, and F. Royer. "The Luminosity Calibration of the HR Diagram." Highlights of Astronomy 11, no. 1 (1998): 558. http://dx.doi.org/10.1017/s1539299600022139.

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An extensive work on the luminosity calibration of the HR diagram has been performed using the LM method based on the Maximum Likelihood estimation (Luri et al. 1996). The method uses all available information: Hipparcos parallax and proper motion data as well as radial velocities and some measured spectroscopic or photometric parameters related to luminosity. On the other hand, the method takes into account the censorship of the sample and the errors of the data. Finally, it is able to identify and separate in a given sample, groups with different luminosity, kinematical or spatial characteristics providing not only the corresponding luminosity calibration relationship, but also improved individual absolute magnitude estimates.In order to asses how reliable the luminosity calibrations based on the MK spectral classification are, the LM method has been applied to a sample of B to K stars with MK classification selected from the Hipparcos survey. All known binaries, variables and spectroscopically peculiar stars were removed from the sample. The final sample contains 22054 stars. Our results show that the relation between absolute magnitude and luminosity class has a large intrinsic dispersion. As a consequence, the assignation to a star of a mean absolute magnitude given by a MK classification calibration is a rough procedure. It is preferable to use the individual absolute magnitudes estimated using all the available information for each star, like the estimates provided by the LM method (Gómez et al. 1997).

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45

Tamura, Motohide, Yoichi Itoh, Yumiko Oasa, Alan Tokunaga, and Koji Sugitani. "Very Low-Luminosity Objects in Star-Forming Regions." Highlights of Astronomy 11, no. 1 (1998): 423–24. http://dx.doi.org/10.1017/s1539299600021626.

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AbstractIn order to tackle the problems of low-mass end of the initial mass function (IMF) in star-forming regions and the formation mechanisms of brown dwarfs, we have conducted deep infrared surveys of nearby molecular clouds. We have found a significant population of very low-luminosity sources with IR excesses in the Taurus cloud and the Chamaeleon cloud core regions whose extinction corrected J magnitudes are 3 to 8 mag fainter than those of typical T Tauri stars in the same cloud. Some of them are associated with even fainter companions. Follow-up IR spectroscopy has confirmed for the selected sources that their photospheric temperature is around 2000 to 3000 K. Thus, these very low-luminosity young stellar sources are most likely very low-mass T Tauri stars, and some of them might even be young brown dwarfs.

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46

Aragón-Salamanca, A., C. M. Baugh, and G. Kauffmann. "The K-Band Hubble Diagram for the Brightest Cluster Galaxies: A Test of Galaxy Formation Models." Symposium - International Astronomical Union 186 (1999): 407. http://dx.doi.org/10.1017/s007418090011321x.

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We analyze the K-band Hubble diagram for a sample of brightest cluster galaxies (BCGs) in the redshift range 0 < z < 1. We confirm that the scatter in the absolute magnitudes of the galaxies is small (0.3 magnitudes). The BCGs exhibit very little luminosity evolution in this redshift range: if q0 = 0.0 we detect no luminosity evolution; for q0 = 0.5 we measure a small negative evolution (i.e., BCGs were about 0.5 magnitudes fainter at z = 1 than today). If the mass in stars of these galaxies had remained constant over this period of time, substantial positive luminosity evolution would be expected: BCGs should have been brighter in the past since their stars were younger. A likely explanation for the observed zero or negative evolution is that the stellar mass of the BCGs has been assembled over time through merging and accretion, as expected in hierarchical models of galaxy formation. The colour evolution of the BCGs is consistent with that of an old stellar population (zform > 2) that is evolving passively. We can thus use evolutionary population synthesis models to estimate the rate of growth in stellar mass for these systems. We find that the stellar mass in a typical BCG has grown by a factor ≃ 2 since z ≃ 1 if q0 = 0.0 or by factor ≃ 4 if q0 = 0.5. These results are in remarkably good agreement with the predictions of semi-analytic models of galaxy formation and evolution set in the context of a hierarchical scenario for structure formation.

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47

Arnaboldi, Magda, Enrica Iodice, Frederick Bournaud, Francoise Combes, Linda S. Sparke, Wim Van Driel, and Massimo Capaccioli. "Polar Ring Galaxies and the Tully-Fisher relation: implications for the dark halo shape." Symposium - International Astronomical Union 220 (2004): 405–10. http://dx.doi.org/10.1017/s007418090018372x.

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We have investigated the Tully-Fisher relation for Polar Ring Galaxies (PRGs), based on near infrared, optical and Hi data available for a sample of these peculiar objects. The total K-band luminosity, which mainly comes from the central host galaxy, and the measured Hi linewidth at 20% of the peak line flux density, which traces the potential in the polar plane, place most polar rings of the sample far from the Tully-Fisher relation defined for spiral galaxies, with many PRGs showing larger Hi line-widths than expected for the observed K band luminosity. This result is confirmed by a larger sample of objects, based on B-band data. This observational evidence may be related to the dark halo shape and orientation in these systems, which we study by numerical modeling of PRG formation and dynamics: the larger rotation velocities observed in PRGs can be explained by a flattened polar halo, aligned with the polar ring.

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48

Telnov, V. I. "A high-luminosity superconducting twin e⁺e^- linear collider with energy recovery." Journal of Instrumentation 16, no. 12 (December 1, 2021): P12025. http://dx.doi.org/10.1088/1748-0221/16/12/p12025.

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Abstract Superconducting technology makes it possible to build a high energy e+e- linear collider with energy recovery (ERLC) and reusable beams. To avoid parasitic collisions inside the linacs, a twin (dual) LC is proposed. In this article, I consider the principle scheme of the collider and estimate the achievable luminosity, which is limited by collision effects and available power. Such a collider can operate in a duty cycle (DC) and in a continuous (CW) modes, if sufficient power. With current SC Nb technology (T = 1.8 K, f RF = 1.3 GHz, used for ILC) and with power P = 100 MW, a luminosity L ∼ 0.33 × 1036 cm-2 s-1 is possible at the Higgs factory with 2E 0 = 250 GeV. Using superconductors operating at 4.5 K with high Q 0 values, such as Nb3Sn, and f RF = 0.65 GHz, the luminosity can reach L ∼ 1.4 × 1036 cm-2 s-1 at 2EE0 = 250 GeV (with P = 100 MW) and L ∼ 0.8 × 1036 cm-2 s-1 at 2E 0 = 500 GeV (with P = 150 MW), which is almost two orders of magnitude greater than at the ILC, where the beams are used only once. This technology requires additional efforts to obtain the required parameters and reliably operation. Such a collider would be the best machine for precision Higgs studies, including the measurement of Higgs self-coupling.

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Cuntz, Manfred, and Zhaopeng Wang. "The Mass–Luminosity Relation for a Refined Set of Late-K/M Dwarfs." Research Notes of the AAS 2, no. 1 (January 29, 2018): 19. http://dx.doi.org/10.3847/2515-5172/aaaa67.

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50

Gardner, J. P., R. M. Sharples, C. S. Frenk, and B. E. Carrasco. "A Wide-Field [ITAL]K[/ITAL]-band Survey: The Luminosity Function of Galaxies." Astrophysical Journal 480, no. 2 (May 10, 1997): L99—L102. http://dx.doi.org/10.1086/310630.

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