Статті в журналах: "Galaxy feedback"

1

McNamara, B. R. "Feedback on Galaxy Formation." Science 341, no. 6150 (September 5, 2013): 1073–75. http://dx.doi.org/10.1126/science.1243114.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Silk, Joseph. "Feedback in Galaxy Formation." Proceedings of the International Astronomical Union 6, S277 (December 2010): 273–81. http://dx.doi.org/10.1017/s1743921311022939.

Повний текст джерела

Анотація:

AbstractI review the outstanding problems in galaxy formation theory, and the role of feedback in resolving them. I address the efficiency of star formation, the galactic star formation rate, and the roles of supernovae and supermassive black holes.

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Murray, Norman. "Feedback and Outflows." Proceedings of the International Astronomical Union 8, S292 (August 2012): 343–50. http://dx.doi.org/10.1017/s1743921313001671.

Повний текст джерела

Анотація:

AbstractThe low stellar and gas mass fractions, low galaxy-wide star formation rates (relative to galactic dynamical times) and observations of rapid outflows from galaxies, all suggest that stars and active galactic nuclei violently alter the state of the interstellar and even inter-halo gas in galaxies. I argue that the low galaxy wide star formation rates are not the result of turbulent suppression of star formation on small scale, but rather the result of a balance between dynamical pressure and the force (or rate of momentum deposition) provided by stellar feedback, either in the form of radiation pressure or by supernovae. Galaxy scale winds can also be driven by feedback, either from stars or active galactic nuclei, although the exact mechanisms involved are still not well determined.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Hopkins, Philip F. "Quasars, Feedback, and Galaxy Formation." Proceedings of the International Astronomical Union 5, S267 (August 2009): 421–28. http://dx.doi.org/10.1017/s1743921310006940.

Повний текст джерела

Анотація:

AbstractRecent observations of tight correlations between supermassive black hole masses and the properties of their host galaxies demonstrate that black holes and bulges are co-eval and have motivated theoretical models in which feedback from AGN activity regulates the black hole and host galaxy evolution. Combining simulations, analytic models, and recent observations, answers to a number of questions are starting to take shape: how do AGN get triggered? How long do they live? What are typical light curves and what sets them? Is feedback necessary and/or sufficient to regulate BH growth? What effects does that feedback have on the host galaxy? On the host halo? All of this also highlights questions that remain wide open: how does gas get from a few pc to the AGN? What are the actual microphysical mechanisms of feedback? What is the tradeoff between stellar and AGN feedback? And, if there are different “modes” of feedback, where/when are each important?

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Nayakshin, Sergei, Mark I. Wilkinson, and Andrew King. "Competitive feedback in galaxy formation." Monthly Notices of the Royal Astronomical Society: Letters 398, no. 1 (September 1, 2009): L54—L57. http://dx.doi.org/10.1111/j.1745-3933.2009.00709.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Wagner, A. Y., G. V. Bicknell, M. Umemura, R. S. Sutherland, and J. Silk. "Galaxy-scale AGN feedback - theory." Astronomische Nachrichten 337, no. 1-2 (February 2016): 167–74. http://dx.doi.org/10.1002/asna.201512287.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Ciotti, Luca, Jeremiah P. Ostriker, Andrea Negri, Silvia Pellegrini, Silvia Posacki, and Greg Novak. "AGN feedback and star formation in ETGs: negative and positive feedback." Proceedings of the International Astronomical Union 11, S315 (August 2015): 224–27. http://dx.doi.org/10.1017/s1743921316007535.

Повний текст джерела

Анотація:

AbstractAGN feedback from supermassive black holes (SMBHs) at the center of early type galaxies is commonly invoked as the explanation for the quenching of star formation in these systems. The situation is complicated by the significant amount of mass injected in the galaxy by the evolving stellar population over cosmological times. In absence of feedback, this mass would lead to unobserved galactic cooling flows, and to SMBHs two orders of magnitude more massive than observed. By using high-resolution 2D hydrodynamical simulations with radiative transport and star formation in state-of-the-art galaxy models, we show how the intermittent AGN feedback is highly structured on spatial and temporal scales, and how its effects are not only negative (shutting down the recurrent cooling episodes of the ISM), but also positive, inducing star formation in the inner regions of the host galaxy.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Bicknell, G. V., B. R. McNamara, M. A. Nawaz, R. S. Sutherland, M. Umemura, and A. Y. Wagner. "AGN feedback by relativistic jets." Proceedings of the International Astronomical Union 10, S313 (September 2014): 101–7. http://dx.doi.org/10.1017/s174392131500201x.

Повний текст джерела

Анотація:

AbstractFeedback provided by relativistic jets may be effective in shaping the galaxy luminosity function. The quenching mode (quasar mode) at redshifts ~2-3 potentially disperses gas in star-forming galaxies. The maintenance mode (radio mode) heats the gas in galaxy clusters counteracting cooling flows. A number of authors have examined the effect of relativistic jets in dispersing clouds in the kpc-scale inhomogeneous interstellar medium of evolving galaxies. We have also investigated a particular case of maintenance-mode feedback in our simulation of the iconic radio galaxy / cooling flow cluster Hydra A. Modelling of the knots produced by the jets in the inner 10 kpc provides an estimate of 0.8 – 0.9 c for the velocities of the jets in agreement with other velocity estimates for FR1 jets. The addition of jet precession provides realistic simulations of the morphology of the Hydra A radio source and raises interesting questions as to the role of black hole and disk precession, in general, in galaxy formation.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Shabala, Stanislav, and Paul Alexander. "RADIO SOURCE FEEDBACK IN GALAXY EVOLUTION." Astrophysical Journal 699, no. 1 (June 12, 2009): 525–38. http://dx.doi.org/10.1088/0004-637x/699/1/525.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Mashchenko, S., J. Wadsley, and H. M. P. Couchman. "Stellar Feedback in Dwarf Galaxy Formation." Science 319, no. 5860 (January 11, 2008): 174–77. http://dx.doi.org/10.1126/science.1148666.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Fabian, A. C. "Cosmic Feedback from AGN." Proceedings of the International Astronomical Union 5, S267 (August 2009): 341–49. http://dx.doi.org/10.1017/s1743921310006691.

Повний текст джерела

Анотація:

AbstractAccretion onto the massive black hole at the centre of a galaxy can feed energy and momentum into its surroundings via radiation, winds, and jets. Feedback due to radiation pressure can lock the mass of the black hole onto the MBH–σ relation, and shape the final stellar bulge of the galaxy. Feedback due to the kinetic power of jets can prevent massive galaxies greatly increasing their stellar mass by heating gas, which would otherwise cool radiatively. The mechanisms involved in cosmic feedback are discussed and illustrated with observations.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Combes, Françcoise. "Models of AGN feedback." Proceedings of the International Astronomical Union 10, S309 (July 2014): 182–89. http://dx.doi.org/10.1017/s1743921314009636.

Повний текст джерела

Анотація:

AbstractThe physical processes responsible of sweeping up the surrounding gas in the host galaxy of an AGN, and able in some circumstances to expel it from the galaxy, are not yet well known. The various mechanisms are briefly reviewed: quasar or radio modes, either momentum-conserving outflows, energy-conserving outflows, or intermediate. They are confronted to observations, to know whether they can explain the M-sigma relation, quench the star formation or whether they can also provide some positive feedback and how the black hole accretion history is related to that of star formation.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Ceverino, Daniel, та Anatoly Klypin. "The role of stellar feedback in the formation of galactic disks and bulges in a ΛCDM Universe". Proceedings of the International Astronomical Union 3, S245 (липень 2007): 33–34. http://dx.doi.org/10.1017/s1743921308017213.

Повний текст джерела

Анотація:

AbstractAlthough supernova explosions and stellar winds happens at scales bellow 100 pc, they affect the interstellar medium (ISM) and galaxy formation. We use cosmological N-body+Hydrodynamics simulations of galaxy formation, as well as simulations of the ISM to study the effect of stellar feedback on galactic scales. Stellar feedback maintains gas with temperatures above a million degrees. This gas fills bubbles, super-bubbles and chimneys. Our model of feedback, in which 10%–30% of the feedback energy is coming from runaway stars, reproduces this hot gas only if the resolution is better than 50 pc. This is 10 times better than the typical resolution in cosmological simulations of galaxy formation. Only with this resolution, the effect of stellar feedback in galaxy formation is resolved without any assumption about sub-resolution physics. Stellar feedback can regulate the formation of bulges and can shape the inner parts of the rotation curve.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Kolokythas, Konstantinos. "AGN feedback and galaxy evolution in nearby galaxy groups using CLoGS." Proceedings of the International Astronomical Union 15, S359 (March 2020): 180–81. http://dx.doi.org/10.1017/s1743921320001507.

Повний текст джерела

Анотація:

AbstractMuch of the evolution of galaxies takes place in groups where feedback has the greatest impact on galaxy formation and evolution. We summarize results from studies of the central brightest group early-type galaxies (BGEs) of an optically selected, statistically complete sample of 53 nearby groups (<80 Mpc; CLoGS sample), observed in radio 235/610 MHz (GMRT), CO (IRAM/APEX) and X-ray (Chandra and XMM-Newton) frequencies. We characterize the radio-AGN population of the BGEs, their group X-ray environment and examine the jet energetics impact on the intra-group gas. We discuss the relation between the radio properties of the BGEs and their group X-ray environment along with the relation between the molecular gas content and the star formation that BGEs present. We conclude that AGN feedback in groups can appear as relatively gentle near-continuous thermal regulation, but also as extreme AGN activity which could potentially shut down cooling for longer periods.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Salcido, Jaime, Richard G. Bower, and Tom Theuns. "How feedback shapes galaxies: an analytic model." Monthly Notices of the Royal Astronomical Society 491, no. 4 (November 22, 2019): 5083–100. http://dx.doi.org/10.1093/mnras/stz3156.

Повний текст джерела

Анотація:

ABSTRACT We introduce a simple analytic model of galaxy formation that links the growth of dark matter haloes in a cosmological background to the build-up of stellar mass within them. The model aims to identify the physical processes that drive the galaxy-halo co-evolution through cosmic time. The model restricts the role of baryonic astrophysics to setting the relation between galaxies and their haloes. Using this approach, galaxy properties can be directly predicted from the growth of their host dark matter haloes. We explore models in which the effective star formation efficiency within haloes is a function of mass (or virial temperature) and independent of time. Despite its simplicity, the model reproduces self-consistently the shape and evolution of the cosmic star formation rate density, the specific star formation rate of galaxies, and the galaxy stellar mass function, both at the present time and at high redshifts. By systematically varying the effective star formation efficiency in the model, we explore the emergence of the characteristic shape of the galaxy stellar mass function. The origin of the observed double Schechter function at low redshifts is naturally explained by two efficiency regimes in the stellar to halo mass relation, namely, a stellar feedback regulated stage, and a supermassive black hole regulated stage. By providing a set of analytic differential equations, the model can be easily extended and inverted, allowing the roles and impact of astrophysics and cosmology to be explored and understood.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Eckert, Dominique, Massimo Gaspari, Fabio Gastaldello, Amandine M. C. Le Brun, and Ewan O’Sullivan. "Feedback from Active Galactic Nuclei in Galaxy Groups." Universe 7, no. 5 (May 11, 2021): 142. http://dx.doi.org/10.3390/universe7050142.

Повний текст джерела

Анотація:

The co-evolution between supermassive black holes and their environment is most directly traced by the hot atmospheres of dark matter halos. The cooling of the hot atmosphere supplies the central regions with fresh gas, igniting active galactic nuclei (AGN) with long duty cycles. Outflows from the central engine tightly couple with the surrounding gaseous medium and provide the dominant heating source preventing runaway cooling by carving cavities and driving shocks across the medium. The AGN feedback loop is a key feature of all modern galaxy evolution models. Here, we review our knowledge of the AGN feedback process in the specific context of galaxy groups. Galaxy groups are uniquely suited to constrain the mechanisms governing the cooling–heating balance. Unlike in more massive halos, the energy that is supplied by the central AGN to the hot intragroup medium can exceed the gravitational binding energy of halo gas particles. We report on the state-of-the-art in observations of the feedback phenomenon and in theoretical models of the heating-cooling balance in galaxy groups. We also describe how our knowledge of the AGN feedback process impacts galaxy evolution models and large-scale baryon distributions. Finally, we discuss how new instrumentation will answer key open questions on the topic.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Heap, Sara. "Role of massive stars in the evolution of primitive galaxies." Proceedings of the International Astronomical Union 10, H16 (August 2012): 370. http://dx.doi.org/10.1017/s1743921314011429.

Повний текст джерела

Анотація:

AbstractAn important factor controlling galaxy evolution is feedback from massive stars. It is believed that the nature and intensity of stellar feedback changes as a function of galaxy mass and metallicity. At low mass and metallicity, feedback from massive stars is mainly in the form of photoionizing radiation. At higher mass and metallicity, it is in stellar winds. I Zw 18 is a local blue, compact dwarf galaxy that meets the requirements for a primitive galaxy: low halo mass <109M⊙, strong photoionizing radiation, no galactic outflow, and very low metallicity, log(O/H)+12=7.2. We will describe the properties of massive stars and their role in the evolution of I Zw 18, based on analysis of ultraviolet images and spectra obtained with HST.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Shimizu, Ikkoh, Keita Todoroki, Hidenobu Yajima, and Kentaro Nagamine. "Osaka feedback model: isolated disc galaxy simulations." Monthly Notices of the Royal Astronomical Society 484, no. 2 (January 16, 2019): 2632–55. http://dx.doi.org/10.1093/mnras/stz098.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Bhattacharya, Suman, Tiziana Di Matteo, and Arthur Kosowsky. "Effects of quasar feedback in galaxy groups." Monthly Notices of the Royal Astronomical Society 389, no. 1 (September 1, 2008): 34–44. http://dx.doi.org/10.1111/j.1365-2966.2008.13555.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Silk, Joseph. "Feedback, Disk Self‐Regulation, and Galaxy Formation." Astrophysical Journal 481, no. 2 (June 1997): 703–9. http://dx.doi.org/10.1086/304073.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Monaco, Pierluigi. "Physical regimes for feedback in galaxy formation." Monthly Notices of the Royal Astronomical Society 352, no. 1 (July 2004): 181–204. http://dx.doi.org/10.1111/j.1365-2966.2004.07916.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Graziani, L., S. Salvadori, R. Schneider, D. Kawata, M. de Bennassuti, and A. Maselli. "Galaxy formation with radiative and chemical feedback." Monthly Notices of the Royal Astronomical Society 449, no. 3 (April 8, 2015): 3137–48. http://dx.doi.org/10.1093/mnras/stv494.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Cattaneo, Andrea. "Feedback and its role in galaxy formation." Nature Astronomy 3, no. 10 (September 25, 2019): 896–97. http://dx.doi.org/10.1038/s41550-019-0904-y.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Keller, B. W., J. Wadsley, S. M. Benincasa, and H. M. P. Couchman. "A superbubble feedback model for galaxy simulations." Monthly Notices of the Royal Astronomical Society 442, no. 4 (June 28, 2014): 3013–25. http://dx.doi.org/10.1093/mnras/stu1058.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Bourne, Martin A. "Simulation of AGN feedback and its impact on galaxies." Proceedings of the International Astronomical Union 12, S324 (September 2016): 231–34. http://dx.doi.org/10.1017/s1743921317001508.

Повний текст джерела

Анотація:

AbstractFeedback released during the growth of supermassive black holes is expected to play a key role in shaping black hole-host galaxy co-evolution. Powerful, accretion disc driven winds have been invoked to explain both observed scaling relations (e.g., M − σ) and large-scale outflows with mass outflow rates of ~ 100 − 1000 M⊙ yr−1 and momentum rates of up to ~ 30 LAGN/c. Critically, how these winds couple to the host galaxy depends on if they are momentum or energy conserving. I outline observational signatures that could distinguish between these regimes and discuss their roles in establishing galaxy properties. Furthermore, I discuss high-resolution simulations exploring feedback in a multi-phase medium, highlighting how structural properties of galaxies can impact feedback efficiency. Finally, feedback, in the form of collimated jets, is expected to regulate cooling in galaxy clusters. I discuss new simulations of jet feedback using the moving-mesh code AREPO and outline the scope of our new study.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Hirschmann, Michaela, and Gabriella De Lucia. "The impact of stellar feedback on high-z galaxy populations." Proceedings of the International Astronomical Union 11, S319 (August 2015): 26. http://dx.doi.org/10.1017/s1743921315009928.

Повний текст джерела

Анотація:

AbstractOne major deficiency of state-of-the-art galaxy formation models consists in their inability of capturing the observed galaxy downsizing trend significantly over-estimating the number density of low-mass galaxies, in particular at high redshifts. Employing an enhanced galaxy formation model with a full chemical enrichment scheme (DeLucia et al., 2014), we present an improved model for stellar feedback (based on parametrizations from cosmological zoom simulations), in which strong gas outflows occur due to bursty star formation at high z, while star formation is mainly “quiescent” not causing any significant outflows anymore at low z. Due to the stronger gas outflows at high z, early star formation is strongly delayed towards later times. This helps to sufficiently detach the evolution of galaxy growth from the hiearchical dark matter assembly resulting in a fairly good agreement with the evolution of the observed stellar mass function (SMF, see Fig. 1). With our new feedback scheme, we can also successfully reproduce many other observational constraints, such as the metallicity content, the cold gas fractions or the quiescent galaxy fractions at both low and high redshifts. The resulting new-generation galaxy catalogues (Hirschmann et al., in prep) based on that model are expected to significantly contribute to the interpretation of current and up-coming large-scale surveys (HST, JWST, Euclid). This will, in turn, provide a rapid verification and refinement of our modeling.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Soussana, Adam, Nora Elisa Chisari, Sandrine Codis, Ricarda S. Beckmann, Yohan Dubois, Julien Devriendt, Sebastien Peirani, Clotilde Laigle, Christophe Pichon, and Adrianne Slyz. "The impact of AGN feedback on galaxy intrinsic alignments in the Horizon simulations." Monthly Notices of the Royal Astronomical Society 492, no. 3 (January 17, 2020): 4268–82. http://dx.doi.org/10.1093/mnras/staa045.

Повний текст джерела

Анотація:

ABSTRACT The intrinsic correlations of galaxy shapes and orientations across the large-scale structure of the Universe are a known contaminant to weak gravitational lensing. They are known to be dependent on galaxy properties, such as their mass and morphologies. The complex interplay between alignments and the physical processes that drive galaxy evolution remains vastly unexplored. We assess the sensitivity of intrinsic alignments (shapes and angular momenta) to active galactic nuclei (AGN) feedback by comparing galaxy alignment in twin runs of the cosmological hydrodynamical Horizon simulation, which do and do not include AGN feedback, respectively. We measure intrinsic alignments in three dimensions and in projection at $z$ = 0 and $z$ = 1. We find that the projected alignment signal of all galaxies with resolved shapes with respect to the density field in the simulation is robust to AGN feedback, thus giving similar predictions for contamination to weak lensing. The relative alignment of galaxy shapes around galaxy positions is however significantly impacted, especially when considering high-mass ellipsoids. Using a sample of galaxy ‘twins’ across simulations, we determine that AGN changes both the galaxy selection and their actual alignments. Finally, we measure the alignments of angular momenta of galaxies with their nearest filament. Overall, these are more significant in the presence of AGN as a result of the higher abundance of massive pressure-supported galaxies.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Hamann, Fred, Serena Perrotta, and Nadia Zakamska. "Outflows & Feedback from Extremely Red Quasars." Proceedings of the International Astronomical Union 15, S359 (March 2020): 232–37. http://dx.doi.org/10.1017/s1743921320004330.

Повний текст джерела

Анотація:

AbstractFeedback from accreting supermassive black holes is often invoked in galaxy evolution models to inhibit star formation, truncate galaxy growth, and establish the observed black-hole/bulge mass correlation. We are studying outflows and feedback in a unique sample of extremely red quasars (ERQs) during the peak epoch of galaxy formation (at redshifts 2.3 < z < 3.4). We identified ERQs in the Sloan Digital Sky Survey III (SDSS-III) Baryon Oscillation Spectroscopic Survey (BOSS) quasar catalog based on their extremely red i–W3 colors, but we find that ERQs typically have a suite of other extreme properties including 1) a high incidence of blueshifted broad absorption lines, 2) broad emission lines with unusually large rest equivalent widths (REWs), peculiar “wingless” profiles, and frequent large blueshifts (reaching ˜8740 km s-1), and 3) characteristically very broad and blueshifted [OIII] 4959,5007Å lines that trace ionized outflows at speeds up to ˜6700 km s-1. We propose that these ERQs represent a young quasar population with powerful outflows on the precipice of causing important disruptive feedback effects in their host galaxies.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Torrey, Paul, Philip F. Hopkins, Claude-André Faucher-Giguère, Daniel Anglés-Alcázar, Eliot Quataert, Xiangcheng Ma, Robert Feldmann, Dusan Keres, and Norm Murray. "The impact of AGN wind feedback in simulations of isolated galaxies with a multiphase ISM." Monthly Notices of the Royal Astronomical Society 497, no. 4 (August 10, 2020): 5292–308. http://dx.doi.org/10.1093/mnras/staa2222.

Повний текст джерела

Анотація:

ABSTRACT Accreting black holes can drive fast and energetic nuclear winds that may be an important feedback mechanism associated with active galactic nuclei (AGN). In this paper, we implement a scheme for capturing feedback from these fast nuclear winds and examine their impact in simulations of isolated disc galaxies. Stellar feedback is modelled using the Feedback In Realistic Environments (fire) physics and produces a realistic multiphase interstellar medium (ISM). We find that AGN winds drive the formation of a low-density, high-temperature central gas cavity that is broadly consistent with analytic model expectations. The effects of AGN feedback on the host galaxy are a strong function of the wind kinetic power and momentum. Low- and moderate-luminosity AGN do not have a significant effect on their host galaxy: the AGN winds inefficiently couple to the ambient ISM and instead a significant fraction of their energy vents in the polar direction. For such massive black holes, accretion near the Eddington limit can have a dramatic impact on the host galaxy ISM: if AGN wind feedback acts for ≳20–30 Myr, the inner ∼1–10 kpc of the ISM is disrupted and the global galaxy star formation rate is significantly reduced. We quantify the properties of the resulting galaxy-scale outflows and find that the radial momentum in the outflow is boosted by a factor of ∼2–3 relative to that initially supplied in the AGN wind for strong feedback scenarios, decreasing below unity for less energetic winds. In contrast to observations, however, the outflows are primarily hot, with very little atomic or molecular gas. We conjecture that merging galaxies and high-redshift galaxies, which have more turbulent and thicker discs and very different nuclear gas geometries, may be even more disrupted by AGN winds than found in our simulations.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Juneau, Stéphanie, Andy D. Goulding, Julie Banfield, Stefano Bianchi, Pierre-Alain Duc, I.-Ting Ho, Michael A. Dopita, et al. "The Black Hole–Galaxy Connection: Interplay between Feedback, Obscuration, and Host Galaxy Substructure." Astrophysical Journal 925, no. 2 (February 1, 2022): 203. http://dx.doi.org/10.3847/1538-4357/ac425f.

Повний текст джерела

Анотація:

Abstract There is growing evidence for physical influence between supermassive black holes and their host galaxies. We present a case study of the nearby galaxy NGC 7582, for which we find evidence that galactic substructure plays an important role in affecting the collimation of ionized outflows as well as contributing to the heavy active galactic nucleus (AGN) obscuration. This result contrasts with a simple, small-scale AGN torus model, according to which AGN-wind collimation may take place inside the torus itself, at subparsec scales. Using 3D spectroscopy with the Multi Unit Spectroscopic Explorer instrument, we probe the kinematics of the stellar and ionized gas components as well as the ionization state of the gas from a combination of emission-line ratios. We report for the first time a kinematically distinct core (KDC) in NGC 7582, on a scale of ∼600 pc. This KDC coincides spatially with dust lanes and starbursting complexes previously observed. We interpret it as a circumnuclear ring of stars and dusty, gas-rich material. We obtain a clear view of the outflowing cones over kiloparsec scales and demonstrate that they are predominantly photoionized by the central engine. We detect the back cone (behind the galaxy) and confirm previous results of a large nuclear obscuration of both the stellar continuum and H ii regions. While we tentatively associate the presence of the KDC with a large-scale bar and/or a minor galaxy merger, we stress the importance of gaining a better understanding of the role of galaxy substructure in controlling the fueling, feedback, and obscuration of AGNs.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Bharadwaj, V., T. H. Reiprich, G. Schellenberger, H. J. Eckmiller, R. Mittal, and H. Israel. "Intracluster medium cooling, AGN feedback, and brightest cluster galaxy properties of galaxy groups." Astronomy & Astrophysics 572 (November 27, 2014): A46. http://dx.doi.org/10.1051/0004-6361/201322684.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Caproni, Anderson, and Gustavo Amaral Lanfranchi. "The gas-loss evolution in dwarf spheroidal galaxies: Supernova feedback and environment effects in the case of the local group galaxy Ursa Minor." Proceedings of the International Astronomical Union 15, S359 (March 2020): 117–18. http://dx.doi.org/10.1017/s1743921320002161.

Повний текст джерела

Анотація:

AbstractIn this work, we performed two distinct non-cosmological, three-dimensional hydrodynamic simulations that evolved the gas component of a galaxy similar to the classical dwarf spheroidal galaxy Ursa Minor. Both simulations take into account types II and Ia supernovae feedback constrained by chemical evolution models, while ram-pressure stripping mechanism is added into one of them considering an intergalactic medium and a galactic velocity that resemble what is observed nowadays for the Ursa Minor galaxy. Our results show no difference in the amount of gas left inside the galaxy until 400 Myr of evolution. Moreover, the ram-pressure wind was stalled and inverted by thermal pressure of the interstellar medium and supernovae feedback during the same interval.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Keller, B. W., J. Wadsley, and H. M. P. Couchman. "Cosmological galaxy evolution with superbubble feedback – I. Realistic galaxies with moderate feedback." Monthly Notices of the Royal Astronomical Society 453, no. 4 (September 9, 2015): 3500–3510. http://dx.doi.org/10.1093/mnras/stv1789.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Rubinur, Khatun, Mousumi Das, Preeti Kharb, and P. T. Rahne. "Understanding galaxy mergers and AGN feedback with UVIT." Proceedings of the International Astronomical Union 15, S356 (October 2019): 345–47. http://dx.doi.org/10.1017/s1743921320003300.

Повний текст джерела

Анотація:

AbstractSimulations expect an enhanced star-formation and active galactic nuclei (AGN) activity during galaxy mergers, which can lead to formation of binary/dual AGN. AGN feedback can enhance or suppress star-formation. We have carried out a pilot study of a sample of ˜10 dual nuclei galaxies with AstroSat’s Ultraviolet Imaging Telescope (UVIT). Here, we present the initial results for two sample galaxies (Mrk 739, ESO 509) and deep multi-wavelength data of another galaxy (Mrk 212). UVIT observations have revealed signatures of positive AGN feedback in Mrk 739 and Mrk 212, and negative feedback in ESO 509. Deeper UVIT observations have recently been approved; these will provide better constraints on star-formation as well as AGN feedback in these systems.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Hota, Ananda, Pratik Dabhade, Sravani Vaddi, Chiranjib Konar, Sabyasachi Pal, Mamta Gulati, C. S. Stalin, et al. "RAD@home citizen science discovery of an active galactic nucleus spewing a large unipolar radio bubble on to its merging companion galaxy." Monthly Notices of the Royal Astronomical Society: Letters 517, no. 1 (October 12, 2022): L86—L91. http://dx.doi.org/10.1093/mnrasl/slac116.

Повний текст джерела

Анотація:

ABSTRACT Active galactic nucleus (AGN) feedback during galaxy merger has been the most favoured model to explain black hole–galaxy co-evolution. However, how the AGN-driven jet/wind/radiation is coupled with the gas of the merging galaxies, which leads to positive feedback, momentarily enhanced star formation, and subsequently negative feedback, a decline in star formation, is poorly understood. Only a few cases are known where the jet and companion galaxy interaction leads to minor off-axis distortions in the jets and enhanced star formation in the gas-rich minor companions. Here, we briefly report one extraordinary case, RAD12, discovered by RAD@home citizen science collaboratory, where for the first time a radio jet–driven bubble (∼ 137 kpc) is showing a symmetric reflection after hitting the incoming galaxy which is not a gas-rich minor but a gas-poor early-type galaxy in a major merger. Surprisingly, neither positive feedback nor any radio lobe on the counter jet side, if any, is detected. It is puzzling if RAD12 is a genuine one-sided jet or a case of radio lobe trapped, compressed and re-accelerated by shocks during the merger. This is the first imaging study of RAD12 presenting follow-up with the Giant Metrewave Radio Telescope, archival MeerKAT radio data and Canada-France-Hawaii Telescope optical data.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Conselice, Christopher J. "How do Galaxies get their Baryons?" Proceedings of the International Astronomical Union 6, S277 (December 2010): 267–72. http://dx.doi.org/10.1017/s1743921311022927.

Повний текст джерела

Анотація:

AbstractUnderstanding how galaxies obtain baryons, their stars and gas, over cosmic time is traditionally approached in two different ways - theoretically and observationally. In general, observational approaches to galaxy formation include measuring basic galaxy properties, such as luminosities, stellar masses, rotation speeds, star formation rates and how these features evolve through time. Theoretically, cosmologically based models collate the physical effects driving galaxy assembly - mergers of galaxies, accretion of gas, star formation, and feedback, amongst others, to form predictions which are matched to galaxy observables. An alternative approach is to examine directly, in an observational way, the processes driving galaxy assembly, including the effects of feedback. This is a new ‘third way’ towards understanding how galaxies are forming from gas accretion and mergers, and directly probes these effects instead of relying on simulations designed to reproduce observations. This empirical approach towards understanding galaxy formation, including the acquisition history of baryons, displays some significant differences with the latest galaxy formation models, in addition to directly demonstrating the mechanisms by which galaxies form most of their baryonic mass.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Shabala, Stanislav S. "Environmental dependence of radio galaxy populations." Proceedings of the International Astronomical Union 14, A30 (August 2018): 82–85. http://dx.doi.org/10.1017/s174392131900351x.

Повний текст джерела

Анотація:

AbstractSensitive continuum surveys with next-generation interferometers will characterise large samples of radio sources at epochs during which cosmological models predict feedback from radio jets to play an important role in galaxy evolution. Dynamical models of radio sources provide a framework for deriving from observations the radio jet duty cycles and energetics, and hence the energy budget available for feedback. Environment plays a crucial role in determining observable radio source properties, and I briefly summarise recent efforts to combine galaxy formation and jet models in a self-consistent framework. Galaxy clustering estimates from deep optical and NIR observations will provide environment measures needed to interpret the observed radio populations.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

SILK, JOSEPH. "GALAXY FORMATION: THE FIRST 109 YEARS." Modern Physics Letters A 22, no. 25n28 (September 14, 2007): 1865–74. http://dx.doi.org/10.1142/s021773230702508x.

Повний текст джерела

Анотація:

Progress has been made in understanding the origin of spiral galaxies, but elliptical galaxy formation continues to pose many problems. At the centres of ellipticals, one finds supermassive black holes which are occasionally fed by gas accretion from their surroundings and are visible as active galactic nuclei. Negative feedback, due to the outflow from the central black hole during its active phase, terminates the gas supply to the spheroid, thereby resulting in an old stellar population. A contemporaneous phase of positive feedback when the protogalaxy is forming could result in the highly efficient phase of early star formation required by the recent data.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

JAVADI, ATEFEH, JACCO TH VAN LOON, and HABIB KHOSROSHAHI. "SUSTAINING GALAXY EVOLUTION: THE ROLE OF STELLAR FEEDBACK." Publications of The Korean Astronomical Society 30, no. 2 (September 30, 2015): 355–58. http://dx.doi.org/10.5303/pkas.2015.30.2.355.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Shimizu, Ikkoh, Yuri Oku, Kentaro Nagamine, Keita Todoroki, and Hidenobu Yajima. "Erratum: Osaka feedback model: isolated disc galaxy simulations." Monthly Notices of the Royal Astronomical Society 494, no. 1 (April 2, 2020): 598–99. http://dx.doi.org/10.1093/mnras/staa772.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Kannan, R., G. S. Stinson, A. V. Macciò, J. F. Hennawi, R. Woods, J. Wadsley, S. Shen, et al. "Galaxy formation with local photoionization feedback – I. Methods." Monthly Notices of the Royal Astronomical Society 437, no. 3 (November 30, 2013): 2882–93. http://dx.doi.org/10.1093/mnras/stt2098.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Efstathiou, G. "A model of supernova feedback in galaxy formation." Monthly Notices of the Royal Astronomical Society 317, no. 3 (September 21, 2000): 697–719. http://dx.doi.org/10.1046/j.1365-8711.2000.03665.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

43

de Gouveia Dal Pino, Elisabete M., William Clavijo-Bohórquez, and Claudio Melioli. "AGN and Star Formation Feedback in Galaxy Outflows." Proceedings of the International Astronomical Union 14, S342 (May 2018): 229–33. http://dx.doi.org/10.1017/s174392131800604x.

Повний текст джерела

Анотація:

AbstractLarge-scale, broad outflows are common in active galaxies. In systems where star formation coexists with an AGN, it is unclear yet the role that both play on driving the outflows. In this work we present three-dimensional radiative-cooling MHD simulations of the formation of these outflows, considering the feedback from both the AGN and supernovae-driven winds. We find that a large-opening-angle AGN wind develops fountain structures that make the expanding gas to fallback. Furthermore, it exhausts the gas near the nuclear region, extinguishing star formation and accretion within a few 100.000 yr, which establishes the duty cycle of these outflows. The AGN wind accounts for the highest speed features in the outflow with velocities around 10.000 km s−1 (as observed in UFOs), but these are not as cold and dense as required by observations of molecular outflows. The SNe-driven wind is the main responsible for the observed mass-loading of the outflows.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Müller-Sánchez, F., M. Malkan, E. K. S. Hicks, and R. I. Davies. "Measuring AGN Feedback Parameters From Seyfert Galaxy Outflows." Proceedings of the International Astronomical Union 8, S292 (August 2012): 363–66. http://dx.doi.org/10.1017/s1743921313001701.

Повний текст джерела

Анотація:

AbstractWe present results of an on-going program to measure AGN feedback in Seyfert galaxies using integral-field spectroscopy and adaptive optics at Keck Observatory and VLT. Our integral-field observations are revealing AGN-driven outflows of ionized gas in Seyfert galaxies. By resolving the inner 10–40 parsecs, we are successfully modeling them as biconical structures, in which the ionized gas first accelerates and then decelerates. The model parameters provide crucial information on the orientation, geometry and kinematics of the outflows, which is used to estimate mechanical feedback from the AGN: mass and kinetic energy transferred to the interstellar medium. Mass outflow rates can be 102–104 times greater than accretion rates, but in some cases, they are comparable to the estimated inflow rates to the central 10–25 pc, suggesting that the outflows may remove a considerable amount of the infalling gas before it reaches the accretion disk. In half of the AGN measured so far, the kinetic energy of the outflows appears sufficient to provide the eagerly-sought AGN feedback invoked to explain fundamental galaxy properties such as the MBH − σ* relation (0.5–5 Lbol). The other AGN, which lack powerful outflows, also have weaker and more compact radio jets.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Núñez, Alejandro, Jeremiah P. Ostriker, Thorsten Naab, Ludwig Oser, Chia-Yu Hu, and Ena Choi. "Modeling for Stellar Feedback in Galaxy Formation Simulations." Astrophysical Journal 836, no. 2 (February 21, 2017): 204. http://dx.doi.org/10.3847/1538-4357/836/2/204.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Emonts, B. H. C., R. Morganti, M. Villar-Martín, J. Hodgson, E. Brogt, C. N. Tadhunter, E. Mahony, and T. A. Oosterloo. "From galaxy-scale fueling to nuclear-scale feedback." Astronomy & Astrophysics 596 (November 23, 2016): A19. http://dx.doi.org/10.1051/0004-6361/201628592.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Cox, T. J., Patrik Jonsson, Joel R. Primack, and Rachel S. Somerville. "Feedback in simulations of disc-galaxy major mergers." Monthly Notices of the Royal Astronomical Society 373, no. 3 (November 13, 2006): 1013–38. http://dx.doi.org/10.1111/j.1365-2966.2006.11107.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Wagner, A. Y., M. Umemura, and G. V. Bicknell. "ULTRAFAST OUTFLOWS: GALAXY-SCALE ACTIVE GALACTIC NUCLEUS FEEDBACK." Astrophysical Journal 763, no. 1 (January 4, 2013): L18. http://dx.doi.org/10.1088/2041-8205/763/1/l18.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Pasini, T., M. Brüggen, F. de Gasperin, L. Bîrzan, E. O’Sullivan, A. Finoguenov, M. Jarvis, et al. "The relation between the diffuse X-ray luminosity and the radio power of the central AGN in galaxy groups." Monthly Notices of the Royal Astronomical Society 497, no. 2 (July 13, 2020): 2163–74. http://dx.doi.org/10.1093/mnras/staa2049.

Повний текст джерела

Анотація:

ABSTRACT Our understanding of how active galactic nucleus feedback operates in galaxy clusters has improved in recent years owing to large efforts in multiwavelength observations and hydrodynamical simulations. However, it is much less clear how feedback operates in galaxy groups, which have shallower gravitational potentials. In this work, using very deep Very Large Array and new MeerKAT observations from the MIGHTEE survey, we compiled a sample of 247 X-ray selected galaxy groups detected in the COSMOS field. We have studied the relation between the X-ray emission of the intra-group medium and the 1.4 GHz radio emission of the central radio galaxy. For comparison, we have also built a control sample of 142 galaxy clusters using ROSAT and NVSS data. We find that clusters and groups follow the same correlation between X-ray and radio emission. Large radio galaxies hosted in the centres of groups and merging clusters increase the scatter of the distribution. Using statistical tests and Monte Carlo simulations, we show that the correlation is not dominated by biases or selection effects. We also find that galaxy groups are more likely than clusters to host large radio galaxies, perhaps owing to the lower ambient gas density or a more efficient accretion mode. In these groups, radiative cooling of the intra-cluster medium could be less suppressed by active galactic nucleus heating. We conclude that the feedback processes that operate in galaxy clusters are also effective in groups.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Amiri, Amirnezam, Kastytis Zubovas, Alessandro Marconi, Saeed Tavasoli, and Habib G. Khosroshahi. "Effects of AGN feedback on galaxy downsizing in different environments." Proceedings of the International Astronomical Union 15, S359 (March 2020): 163–65. http://dx.doi.org/10.1017/s1743921320001891.

Повний текст джерела

Анотація:

AbstractWe have investigated the role of AGN feedback on galaxy downsizing in cluster and void environments, using the sample from Amieri et al. (2019). Our results indicate that, at least in the local universe, the correlation between black hole mass and (specific) star formation rate is statistically indistinguishable in the two environments. Therefore, the role of the environment in modulating AGN feedback effects on the host galaxy star formation is negligible.

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "Galaxy feedback"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями