Browsing by Subject "STELLAR MASS"

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  • Comparat, J.; Merloni, A.; Salvato, M.; Nandra, K.; Boller, T.; Georgakakis, A.; Finoguenov, A.; Dwelly, T.; Buchner, J.; Del Moro, A.; Clerc, N.; Wang, Y.; Zhao, G.; Prada, F.; Yepes, G.; Brusa, M.; Krumpe, M.; Liu, T. (2019)
    In the context of the upcoming SRG/eROSITA survey, we present an N-body simulation-based mock catalogue for X-ray-selected active galactic nucleus (AGN) samples. The model reproduces the observed hard X-ray AGN luminosity function (XLF) and the soft X-ray logN-logS from redshift 0 to 6. The XLF is reproduced to within +/- 5 per cent and the logN-logS to within +/- 20 per cent. We develop a joint X-ray - optical extinction and classification model. We adopt a set of empirical spectral energy distributions to predict observed magnitudes in the UV, optical, and NIR. With the latest eROSITA all sky survey sensitivity model, we create a high-fidelity full-sky mock catalogue of X-ray AGN. It predicts their distributions in right ascension, declination, redshift, and fluxes. Using empirical medium resolution optical spectral templates and an exposure time calculator, we find that 1.1 x 10(6) (4 x 10(5)) fibre-hours are needed to follow-up spectroscopically from the ground the detected X-ray AGN with an optical magnitude 21 <r <22.8 (22.8 <r <25) with a 4-m (8-m) class multiobject spectroscopic facility. We find that future clustering studies will measure the AGN bias to the per cent level at redshift z <1.2 and should discriminate possible scenarios of galaxy-AGN co-evolution. We predict the accuracy to which the baryon acoustic oscillation standard ruler will be measured using X-ray AGN: better than 3 per cent for AGN between redshift 0.5 to 3 and better than 1 per cent using the Ly alpha forest of X-ray QSOs discovered between redshift 2 and 3. eROSITA will provide an outstanding set of targets for future galaxy evolution and cosmological studies.
  • Allevato, V.; Viitanen, A.; Finoguenov, A.; Civano, F.; Suh, H.; Shankar, F.; Bongiorno, A.; Ferrara, A.; Gilli, R.; Miyaji, T.; Marchesi, S.; Cappelluti, N.; Salvato, M. (2019)
    Aims. We perform clustering measurements of 800 X-ray selected Chandra COSMOS Legacy (CCL) Type 2 active galactic nuclei (AGN) with known spectroscopic redshift to probe the halo mass dependence on AGN host galaxy properties, such as galaxy stellar mass M-star, star formation rate (SFR), and specific black hole accretion rate (BHAR; lambda(BHAR)) in the redshift range z;=;[0-3]. Methods. We split the sample of AGN with known spectroscopic redshits according to M-star, SFR and lambda(BHAR), while matching the distributions in terms of the other parameters, including redshift. We measured the projected two-point correlation function w(p)(r(p)) and modeled the clustering signal, for the different subsamples, with the two-halo term to derive the large-scale bias b and corresponding typical mass of the hosting halo. Results. We find no significant dependence of the large-scale bias and typical halo mass on galaxy stellar mass and specific BHAR for CCL Type 2 AGN at mean z;similar to;1, while a negative dependence on SFR is observed, i.e. lower SFR AGN reside in richer environment. Mock catalogs of AGN, matched to have the same X-ray luminosity, stellar mass, lambda(BHAR), and SFR of CCL Type 2 AGN, almost reproduce the observed M-star - M-h, lambda(BHAR) - M-h and SFR-M-h relations, when assuming a fraction of satellite AGN f(AGN)(sat) similar to 0.15fAGNsat similar to 0.15$ f_{\mathrm{AGN}}{\mathrm{sat}} \sim 0.15 $. This corresponds to a ratio of the probabilities of satellite to central AGN of being active Q;similar to;2. Mock matched normal galaxies follow a slightly steeper M-star - M-h relation, in which low mass mock galaxies reside in less massive halos than mock AGN of similar mass. Moreover, matched mock normal galaxies are less biased than mock AGN with similar specific BHAR and SFR, at least for Q > 1.
  • Furnell, Kate E.; Collins, Chris A.; Kelvin, Lee S.; Clerc, Nicolas; Baldry, Ivan K.; Finoguenov, Alexis; Erfanianfar, Ghazaleh; Comparat, Johan; Schneider, Donald P. (2018)
    We present a sample of 329 low-to intermediate-redshift (0.05 <z
  • Georgakakis, A.; Comparat, J.; Merloni, A.; Ciesla, L.; Aird, J.; Finoguenov, A. (2019)
    A semi-empirical model is presented that describes the distribution of active galactic nuclei (AGNs) on the cosmicweb. It populates dark-matter haloes in N-body simulations (MultiDark) with galaxy stellar masses using empirical relations based on abundance matching techniques, and then paints accretion events on these galaxies using state-of-the-art measurements of the AGN occupation of galaxies. The explicit assumption is that the large-scale distribution of AGN is independent of the physics of black hole fuelling. The model is shown to be consistent with current measurements of the two-point correlation function of AGN samples. It is then used to make inferences on the halo occupation of the AGN population. Mock AGNs are found in haloes with a broad distribution of masses with a mode of approximate to 10(12) h(-1) M-circle dot and a tail extending to cluster-size haloes. The clustering properties of the model AGN depend only weakly on accretion luminosity and redshift. The fraction of satellite AGN in the model increases steeply toward more massive haloes, in contrast with some recent observational results. This discrepancy, if confirmed, could point to a dependence of the halo occupation of AGN on the physics of black hole fuelling.
  • Pasini, T.; Finoguenov, A.; Brueggen, M.; Gaspari, M.; de Gasperin, F.; Gozaliasl, G. (2021)
    We investigate the kinematic properties of a large (N = 998) sample of COSMOS spectroscopic galaxy members distributed among 79 groups. We identify the Brightest Group Galaxies (BGGs) and cross-match our data with the VLA-COSMOS Deep survey at 1.4 GHz, classifying our parent sample into radio/non-radio BGGs and radio/non-radio satellites. The radio luminosity distribution spans from L-R similar to 2 x 10(21) WHz-1 to LR similar to 3 x 10(25) WHz(-1). A phase-space analysis, performed by comparing the velocity ratio (line-of-sight velocity divided by the group velocity dispersion) with the galaxy-group centre offset, reveals that BGGs (radio and non-radio) are mostly (similar to 80 per cent) ancient infallers. Furthermore, the strongest (L-R > 10(23) W Hz(-1)) radio galaxies are always found within 0.2R(vir) from the group centre. Comparing our samples with HORIZON-AGN, we find that the velocities and offsets of simulated galaxies aremore similar to radio BGGs than to non-radio BGGs, albeit statistical tests still highlight significant differences between simulated and real objects. We find that radio BGGs are more likely to be hosted in high-mass groups. Finally, we observe correlations between the powers of BGG radio galaxies and the X-ray temperatures, T-x, and X-ray luminosities, L-x, of the host groups. This supports the existence of a link between the intragroup medium and the central radio source. The occurrence of powerful radio galaxies at group centres can be explained by Chaotic Cold Accretion, as the AGN can feed from both the galactic and intragroup condensation, leading to the observed positive L-R - T-x correlation.
  • Habouzit, Melanie; Li, Yuan; Somerville, Rachel S.; Genel, Shy; Pillepich, Annalisa; Volonteri, Marta; Dave, Romeel; Rosas-Guevara, Yetli; McAlpine, Stuart; Peirani, Sebastien; Hernquist, Lars; Anglés-Alcázar, Daniel; Reines, Amy; Bower, Richard; Dubois, Yohan; Nelson, Dylan; Pichon, Christophe; Vogelsberger, Mark (2021)
    The past decade has seen significant progress in understanding galaxy formation and evolution using large-scale cosmological simulations. While these simulations produce galaxies in overall good agreement with observations, they employ different sub-grid models for galaxies and supermassive black holes (BHs). We investigate the impact of the sub-grid models on the BH mass properties of the Illustris, TNG100, TNG300, Horizon-AGN, EAGLE, and SIMBA simulations, focusing on the M-BH - M-star relation and the BH mass function. All simulations predict tight M-BH - M-star relations, and struggle to produce BHs of M-BH = 109M (circle dot) in most of the simulations. The BH mass function is dominated by efficiently accreting BHs ((log(10) f(Edd) >= -2) at high redshifts, and transitions progressively from the high-mass to the low-mass end to be governed by inactive BHs. The transition time and the contribution of active BHs are different among the simulations, and can be used to evaluate models against observations.
  • Remus, Rhea-Silvia; Dolag, Klaus; Naab, Thorsten; Burkert, Andreas; Hirschmann, Michaela; Hoffmann, Tadziu L.; Johansson, Peter H. (2017)
    We present evidence from cosmological hydrodynamical simulations for a co-evolution of the slope of the total (dark and stellar) mass density profile, gamma (tot), and the dark matter fraction within the half-mass radius, f(DM), in early-type galaxies. The relation can be described as gamma(tot) = A f(DM) + B for all systems at all redshifts. The trend is set by the decreasing importance of gas dissipation towards lower redshifts and for more massive systems. Early-type galaxies are smaller, more concentrated, have lower f(DM) and steeper gamma(tot) at high redshifts and at lower masses for a given redshift; f(DM) and gamma(tot) are good indicators for growth by 'dry' merging. The values for A and B change distinctively for different feedback models, and this relation can be used as a test for such models. A similar correlation exists between gamma(tot) and the stellar mass surface density Sigma(*). A model with weak stellar feedback and feedback from black holes is in best agreement with observations. All simulations, independent of the assumed feedback model, predict steeper gamma(tot) and lower f(DM) at higher redshifts. While the latter is in agreement with the observed trends, the former is in conflict with lensing observations, which indicate constant or decreasing gamma(tot). This discrepancy is shown to be artificial: the observed trends can be reproduced from the simulations using observational methodology to calculate the total density slopes.
  • Balogh, Michael L.; van der Burg, Remco F. J.; Muzzin, Adam; Rudnick, Gregory; Wilson, Gillian; Webb, Kristi; Biviano, Andrea; Boak, Kevin; Cerulo, Pierluigi; Chan, Jeffrey; Cooper, M. C.; Gilbank, David G.; Gwyn, Stephen; Lidman, Chris; Matharu, Jasleen; McGee, Sean L.; Old, Lyndsay; Pintos-Castro, Irene; Reeves, Andrew M. M.; Shipley, Heath; Vulcani, Benedetta; Yee, Howard K. C.; Alonso, M. Victoria; Bellhouse, Callum; Cooke, Kevin C.; Davidson, Anna; De Lucia, Gabriella; Demarco, Ricardo; Drakos, Nicole; Fillingham, Sean P.; Finoguenov, Alexis; Ben Forrest; Golledge, Caelan; Jablonka, Pascale; Garcia, Diego Lambas; McNab, Karen; Muriel, Hernan; Nantais, Julie B.; Noble, Allison; Parker, Laura C.; Petter, Grayson; Poggianti, Bianca M.; Townsend, Melinda; Valotto, Carlos; Webb, Tracy; Zaritsky, Dennis (2021)
    We present the first public data release of the GOGREEN (Gemini Observations of Galaxies in Rich Early Environments) and GCLASS (Gemini CLuster Astrophysics Spectroscopic Survey) surveys of galaxies in dense environments, spanning a redshift range 0.8 <z <1.5. The surveys consist of deep, multiwavelength photometry and extensive Gemini GMOS spectroscopy of galaxies in 26 overdense systems ranging in halo mass from small groups to the most massive clusters. The objective of both projects was primarily to understand how the evolution of galaxies is affected by their environment, and to determine the physical processes that lead to the quenching of star formation. There was an emphasis on obtaining unbiased spectroscopy over a wide stellar mass range (M greater than or similar to 2 x 10(10) M-circle dot), throughout and beyond the cluster virialized regions. The final spectroscopic sample includes 2771 unique objects, of which 2257 have reliable spectroscopic redshifts. Of these, 1704 have redshifts in the range 0.8 <z <1.5, and nearly 800 are confirmed cluster members. Imaging spans the full optical and near-infrared wavelength range, at depths comparable to the UltraVISTA survey, and includes Hubble Space Telescope/Wide Field Camera 3 F160W (GOGREEN) and F140W (GCLASS). This data release includes fully reduced images and spectra, with catalogues of advanced data products including redshifts, line strengths, star formation rates, stellar masses, and rest-frame colours. Here, we present an overview of the data, including an analysis of the spectroscopic completeness and redshift quality.
  • Sales, Laura V.; Navarro, Julio F.; Oman, Kyle; Fattahi, Azadeh; Ferrero, Ismael; Abadi, Mario; Bower, Richard; Crain, Robert A.; Frenk, Carlos S.; Sawala, Till; Schaller, Matthieu; Schaye, Joop; Theuns, Tom; White, Simon D. M. (2017)
    The scaling of disc galaxy rotation velocity with baryonic mass (the 'baryonic Tully-Fisher' relation, BTF) has long confounded galaxy formation models. It is steeper than the M proportional to V-3 scaling relating halo virial masses and circular velocities and its zero-point implies that galaxies comprise a very small fraction of available baryons. Such low galaxy formation efficiencies may, in principle, be explained by winds driven by evolving stars, but the tightness of the BTF relation argues against the substantial scatter expected from such a vigorous feedback mechanism. We use the APOSTLE/EAGLE simulations to show that the BTF relation is well reproduced in Lambda cold dark matter (CDM) simulations that match the size and number of galaxies as a function of stellar mass. In such models, galaxy rotation velocities are proportional to halo virial velocity and the steep velocity-mass dependence results from the decline in galaxy formation efficiency with decreasing halo mass needed to reconcile the CDM halo mass function with the galaxy luminosity function. The scatter in the simulated BTF is smaller than observed, even when considering all simulated galaxies and not just rotationally supported ones. The simulations predict that the BTF should become increasingly steep at the faint end, although the velocity scatter at fixed mass should remain small. Observed galaxies with rotation speeds below similar to 40 km s(-1) seem to deviate from this prediction. We discuss observational biases and modelling uncertainties that may help to explain this disagreement in the context of Lambda CDM models of dwarf galaxy formation.
  • Leslie, Sarah; Schinnerer, Eva; Liu, Daizhong; Magnelli, Benjamin; Algera, Hiddo; Karim, Alexander; Davidzon, Iary; Gozaliasl, Ghassem; Jimenez-Andrade, Eric F.; Lang, Philipp; Sargent, Mark; Novak, Mladen; Groves, Brent; Smolcic, Vernesa; Zamorani, Giovanni; Vaccari, Mattia; Battisti, Andrew; Vardoulaki, Eleni; Peng, Yingjie; Kartaltepe, Jeyhan (2020)
    We provide a coherent, uniform measurement of the evolution of the logarithmic star formation rate (SFR)-stellar mass (M-*) relation, called the main sequence (MS) of star-forming galaxies, for star-forming and all galaxies out to z similar to 5. We measure the MS using mean stacks of 3 GHz radio-continuum images to derive average SFRs for similar to 200,000 mass-selected galaxies at z > 0.3 in the COSMOS field. We describe the MS relation by adopting a new model that incorporates a linear relation at low stellar mass (log(M-*/M-circle dot) <10) and a flattening at high stellar mass that becomes more prominent at low redshift (z <1.5). We find that the SFR density peaks at 1.5 <z <2, and at each epoch there is a characteristic stellar mass (M-* = 1-4 x 10(10)M(circle dot)) that contributes the most to the overall SFR density. This characteristic mass increases with redshift, at least to z similar to 2.5. We find no significant evidence for variations in the MS relation for galaxies in different environments traced by the galaxy number density at 0.3 <z <3, nor for galaxies in X-ray groups at z similar to 0.75. We confirm that massive bulge-dominated galaxies have lower SFRs than disk-dominated galaxies at a fixed stellar mass at z <1.2. As a consequence, the increase in bulge-dominated galaxies in the local star-forming population leads to a flattening of the MS at high stellar masses. This indicates that "mass quenching" is linked with changes in the morphological composition of galaxies at a fixed stellar mass.
  • Daddi, E.; Valentino, F.; Rich, R. M.; Neill, J. D.; Gronke, M.; O'Sullivan, D.; Elbaz, D.; Bournaud, F.; Finoguenov, A.; Marchal, A.; Delvecchio, I.; Jin, S.; Liu, D.; Strazzullo, V.; Calabro, A.; Coogan, R.; D'Eugenio, C.; Gobat, R.; Kalita, B. S.; Laursen, P.; Martin, D. C.; Puglisi, A.; Schinnerer, E.; Wang, T. (2021)
    We have discovered a 300 kpc-wide giant Lyman-alpha (Ly alpha) nebula centered on the massive galaxy group RO-1001 at z=2.91 in the Cosmic Evolution Survey field. Keck Cosmic Web Imager observations reveal three cold gas filaments converging into the center of the potential well of its similar to 4x10(13)M(circle dot) dark matter halo, hosting 1200 M-circle dot yr(-1) of star formation as probed by Atacama Large Millimeter Array and NOrthern Extended Millimeter Array observations. The nebula morphological and kinematics properties and the prevalence of blueshifted components in the Ly alpha spectra are consistent with a scenario of gas accretion. The upper limits on active galactic nuclei activity and overall energetics favor gravity as the primary Ly alpha powering source and infall as the main source of gas flows to the system. Although interpretational difficulties remain, with outflows and likely also photoionization with ensuing recombination still playing a role, this finding provides arguably an ideal environment to quantitatively test models of cold gas accretion and galaxy feeding inside an actively star-forming massive halo at high redshift.
  • Carollo, C. M.; Cibinel, A.; Lilly, S. J.; Pipino, A.; Bonoli, S.; Finoguenov, A.; Miniati, F.; Norberg, P.; Silverman, J. D. (2016)
    We use the low-redshift Zurich Environmental Study (ZENS) catalog to study the dependence of the quenched satellite fraction at 10(10.0) M-circle dot -> 10(11.5) M-circle dot, and of the morphological mix of these quenched satellites, on three different environmental parameters: group halo mass, halo-centric distance, and large-scale structure (LSS) overdensity. Within the two mass bins into which we divide our galaxy sample, the fraction of quenched satellites is more or less independent of halo mass and the surrounding. LSS overdensity, but it increases toward the centers of the halos, as found in previous studies. The morphological mix of these quenched satellites is, however, constant with radial position in the halo, indicating that the well-known morphology-density relation results from the increasing fraction of quenched galaxies toward the centers of halos. If the radial variation in the quenched fraction reflects the action of two quenching processes, one related to mass and the other to environment, then the constancy with radius of the morphological outcome suggests that both have the same effect on the morphologies of the galaxies. Alternatively, mass and environment quenching may be two reflections of a single physical mechanism. The quenched satellites have larger bulge-to-total ratios (B/T) and smaller half-light radii than the star-forming satellites. The bulges in quenched satellites have very similar luminosities and surface brightness profiles, and any mass growth of the bulges associated with quenching cannot greatly change these quantities. The differences in the light-defined B/T and in the galaxy half-light radii are mostly due to differences in the disks, which have lower luminosities in the quenched galaxies. The difference in galaxy half-light radii between quenched and star-forming satellites is however larger than can be explained by uniformly fading the disks following quenching, and the quenched disks have smaller scale lengths than in star-forming satellites. This can be explained either by a differential fading of the disks with galaxy radius or the disks being generally smaller in the past, both of which would be expected in an inside-out disk growth scenario. The overall conclusion is that, at least at low redshifts, the structure of massive quenched satellites at these masses is produced by processes that operate before the quenching takes place. A comparison of our results with semianalytic models argues for a reduction in the efficiency of group halos in quenching their disk satellites and for mechanisms to increase the B/T of low-mass quenched satellites.