scholarly journals Merging massive black holes the right place and the right time

2017 ◽  
Vol 13 (S338) ◽  
pp. 40-45
Author(s):  
Astrid Lamberts
Keyword(s):  
Black Holes ◽  
Star Formation ◽  
Galaxy Formation ◽  
Formation Rate ◽  
Cosmic Time ◽  
Host Galaxy ◽  
Solar Mass ◽  
Massive Galaxies ◽  
Merger Rate ◽  
The Right

AbstractThe LIGO/Virgo detections of gravitational waves from merging black holes of ≃ 30 solar mass suggest progenitor stars of low metallicity (Z/Z⊙≲ 0.3). In this talk I will provide constrains on where the progenitors of GW150914 and GW170104 may have formed, based on advanced models of galaxy formation and evolution combined with binary population synthesis models. First I will combine estimates of galaxy properties (star-forming gas metallicity, star formation rate and merger rate) across cosmic time to predict the low redshift BBH merger rate as a function of present day host galaxy mass, formation redshift of the progenitor system and different progenitor metallicities. I will show that the signal is dominated by binaries formed at the peak of star formation in massive galaxies with and binaries formed recently in dwarf galaxies. Then, I will present what very high resolution hydrodynamic simulations of different galaxy types can learn us about their black hole populations.

scholarly journals Mass and star formation rate of the host galaxies of compact binary mergers across cosmic time

2019 ◽  
Vol 491 (3) ◽  
pp. 3419-3434 ◽  
Author(s):  
M Celeste Artale ◽  
Michela Mapelli ◽  
Yann Bouffanais ◽  
Nicola Giacobbo ◽  
Mario Pasquato ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Cosmic Time ◽  
Stellar Mass ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Compact Binary ◽  
Binary Mergers ◽  
Merger Rate

ABSTRACT We investigate the properties of the host galaxies of compact binary mergers across cosmic time, by means of population-synthesis simulations combined with galaxy catalogues from the eagle suite. We analyse the merger rate per galaxy of binary neutron stars (BNSs), black hole–neutron star binaries (BHNSs), and binary black holes (BBHs) from redshift zero up to six. The binary merger rate per galaxy strongly correlates with the stellar mass of the host galaxy at any redshift considered here. This correlation is significantly steeper for BNSs than for both BHNSs and BBHs. Moreover, we find that the merger rate per galaxy depends also on host galaxy’s star formation rate (SFR) and metallicity. We derive a robust fitting formula that relates the merger rate per galaxy with galaxy’s SFR, stellar mass, and metallicity at different redshifts. The typical masses of the host galaxies increase significantly as redshift decreases, as a consequence of the interplay between delay time distribution of compact binaries and cosmic assembly of galaxies. Finally, we study the evolution of the merger rate density with redshift. At low redshift (z ≤ 0.1) early-type galaxies give a larger contribution to the merger rate density than late-type galaxies. This trend reverts at z ≥ 1.

scholarly journals The AGN-galaxy connection: Low-redshift benchmark & lessons learnt

2019 ◽  
Vol 15 (S352) ◽  
pp. 144-156
Author(s):  
Stéphanie Juneau
Keyword(s):  
Black Hole ◽  
Star Formation ◽  
Spatial Scales ◽  
Formation Rate ◽  
Cosmic Time ◽  
Individual Case ◽  
Host Galaxy ◽  
Gas Reservoir ◽  
Lessons Learnt

AbstractSeveral scenarios have been proposed to describe the physical connection between galaxies and their central active galactic nuclei (AGN). This connection could act on a range of spatial scales and vary across cosmic time. In these proceedings, we consider black hole and galaxy growth and whether that growth is affected by AGN feedback both based on statistical approaches – which reveal general population trends – and based on an individual case study – which gives us a more detailed insight on the physical processes at play. For the statistical approach, we showcase a low-redshift (0.04 < z < 0.2) SDSS sample with AGN classification based on a combination of emission-line diagnostic diagrams, and for which we account for sample selection by using a V/Vmax approach. The trends on the star formation rate - stellar mass (SFR – M*) plane suggest that the most likely connection is a common gas reservoir for star formation and AGN, and that they both decline as the gas reservoir is consumed. The trends established at low-redshift could act as a local benchmark against which to compare higher redshift studies. As a complementary approach, we use a detailed case study of a nearby AGN host with integral field spectroscopy from the VLT/MUSE instrument in order to spatially resolve the interplay between AGN feedback and the host galaxy. We find that the galaxy substructure likely plays a role by collimating and/or obscuring the outflows and radiation from the central engine. Ongoing and future work with 3D spectroscopy will enable us to learn more about galaxy and black hole coevolution. Lastly, we briefly discuss lessons learnt from both approaches.

scholarly journals Spatially-resolved SFR in nearby disk galaxies using IFS data

2016 ◽  
Vol 11 (S321) ◽  
pp. 273-273
Author(s):  
C. Catalán-Torrecilla ◽  
A. Gil de Paz ◽  
A. Castillo-Morales ◽  
J. Méndez-Abreu ◽  
S. Pascual ◽  
...  
Keyword(s):  
Star Formation ◽  
Spatial Information ◽  
Formation Rate ◽  
Cosmic Time ◽  
Stellar Mass ◽  
Massive Galaxies ◽  
Star Forming ◽  
Spatially Resolved ◽  
Open Questions ◽  
Stellar Masses

AbstractExploring the spatial distribution of the star formation rate (SFR) in nearby galaxies is essential to understand their evolution through cosmic time. With this aim in mind, we use a representative sample that contains a variety of morphological types, the CALIFA Integral Field Spectroscopy (IFS) sample. Previous to this work, we have verified that our extinction-corrected Hα measurements successfully reproduce the values derived from other SFR tracers such as Hαobs + IR or UVobs + IR (Catalán-Torrecilla et al. 2015).Now, we go one step further applying 2-dimensional photometric decompositions (Méndez-Abreu et al. (2008), Méndez-Abreu et al. (2014)) over these datacubes. This method allows us to obtain the amount of SFR in the central part (bulge or nuclear source), the bar and the disk, separately. First, we determine the light coming from each component as the ratio between the luminosity in every component (bulge, bar or disk) and the total luminosity of the galaxy. Then, for each galaxy we multiply the IFS datacubes by these previous factors to recover the luminosity in each component. Finally, we derive the spectrum associated to each galaxy component integrating the spatial information in the weighted datacube using an elliptical aperture covering the whole galaxy.2D photometric decomposition applied over 3D datacubes will give us a more detailed understanding of the role that disks play in more massive galaxies. Knowing if the disks in more massive SF galaxies have on average a lower or higher level of star formation activity and how these results are affected by the presence of nuclear bars are still open questions that we can now solve. We describe the behavior of these components in the SFR vs. stellar mass diagram. In particular, we highlight the role of the disks and their contribution to both the integrated SFR for the whole galaxy and the SFR in the disk at different stellar masses in the SFR vs. stellar mass diagram together with their relative position to the star forming Main Sequence.

scholarly journals Star Formation Through Cosmic Time

2006 ◽  
Vol 2 (S235) ◽  
pp. 261-267
Author(s):  
Michael A. Dopita
Keyword(s):  
Star Formation ◽  
Galaxy Formation ◽  
Globular Clusters ◽  
High Redshift ◽  
Cosmic Time ◽  
Star Formation History ◽  
Massive Black Holes ◽  
Massive Galaxies ◽  
History Of ◽  
Population Iii Stars

AbstractThis paper reviews the star formation history of the Universe, from the first stars to the current day, with emphasis on the critical analysis of the techniques that have been used to determine it, especially considering the role of dust. We consider the first population of stars, the Population III stars, were formed at redshifts ranging as high as z ~ 60, the formation of the Globular Clusters, the main epoch of galaxy formation. In the sub-mm galaxies and high-redshift radio galaxies the collapse of massive galaxies was surprisingly rapid, and that the growth of super-massive black holes at their centers provides the energy input to eject the galactic interstellar medium while at the same time precipitating a final burst of star formation and the ejection of their ISM so that the subsequent evolution of these galaxies is passive.

scholarly journals The extended epoch of galaxy formation: Age dating of ~3600 galaxies with 2 < z < 6.5 in the VIMOS Ultra-Deep Survey

2017 ◽  
Vol 602 ◽  
pp. A35 ◽  
Author(s):  
R. Thomas ◽  
O. Le Fèvre ◽  
M. Scodeggio ◽  
P. Cassata ◽  
B. Garilli ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Formation ◽  
Continuous Process ◽  
Formation Rate ◽  
Cosmic Time ◽  
Stellar Mass ◽  
Age Dating ◽  
Joint Analysis ◽  
Physical Parameters ◽  
Deep Survey

In this paper we aim at improving constraints on the epoch of galaxy formation by measuring the ages of 3597 galaxies with reliable spectroscopic redshifts 2 ≤ z ≤ 6.5 in the VIMOS Ultra Deep Survey (VUDS). We derive ages and other physical parameters from the simultaneous fitting with the GOSSIP+ software of observed UV rest-frame spectra and photometric data from the u band up to 4.5 μm using model spectra from composite stellar populations. We perform extensive simulations and conclude that at z ≥ 2 the joint analysis of spectroscopy and photometry, combined with restricted age possibilities when taking the age of the Universe into account, substantially reduces systematic uncertainties and degeneracies in the age derivation; we find that age measurements from this process are reliable. We find that galaxy ages range from very young with a few tens of million years to substantially evolved with ages up to 1.5 Gyr or more. This large age spread is similar for different age definitions including ages corresponding to the last major star formation event, stellar mass-weighted ages, and ages corresponding to the time since the formation of 25% of the stellar mass. We derive the formation redshift zf from the measured ages and find galaxies that may have started forming stars as early as zf ~ 15. We produce the formation redshift function (FzF), the number of galaxies per unit volume formed at a redshift zf, and compare the FzF in increasing observed redshift bins finding a remarkably constant FzF. The FzF is parametrized with (1 + z)ζ, where ζ ≃ 0.58 ± 0.06, indicating a smooth increase of about 2 dex from the earliest redshifts, z ~ 15, to the lowest redshifts of our sample at z ~ 2. Remarkably, this observed increase in the number of forming galaxies is of the same order as the observed rise in the star formation rate density (SFRD). The ratio of the comoving SFRD with the FzF gives an average SFR per galaxy of ~7−17M⊙/yr at z ~ 4−6, in agreement with the measured SFR for galaxies at these redshifts. From the smooth rise in the FzF we infer that the period of galaxy formation extends all the way from the highest possible formation redshifts that we can probe at z ~ 15 down to redshifts z ~ 2. This indicates that galaxy formation is a continuous process over cosmic time, with a higher number of galaxies forming at the peak in SFRD at z ~ 2 than at earlier epochs.

scholarly journals The Star Formation History and Stellar Assembly of High Redshift Galaxies

2006 ◽  
Vol 2 (S235) ◽  
pp. 341-344
Author(s):  
Casey Papovich
Keyword(s):  
Black Holes ◽  
Star Formation ◽  
Galaxy Formation ◽  
High Redshift ◽  
Star Formation History ◽  
Observational Constraints ◽  
Substantial Fraction ◽  
High Redshift Galaxies ◽  
Massive Galaxies ◽  
Formation History

AbstractI discuss current observational constraints on the star-formation and stellar-assembly histories of galaxies at high redshifts. The data on massive galaxies at z < 1 implies that their stellar populations formed at z>2, and that their morphological configuration was in place soon thereafter. Spitzer Space Telescope 24 μ observations indicate that a substantial fraction of massive galaxies at z ~ 1.5–3 have high IR luminosities, suggesting they are rapidly forming stars, accreting material onto supermassive black holes, or both. I compare how observations of these IR–active phases in the histories of massive galaxies constrain current galaxy–formation models.

scholarly journals The elephant in the bathtub: when the physics of star formation regulate the baryon cycle of galaxies

2020 ◽  
Vol 500 (2) ◽  
pp. 2000-2011
Author(s):  
Jindra Gensior ◽  
J M Diederik Kruijssen
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Galaxy Formation ◽  
High Redshift ◽  
Formation Rate ◽  
Cosmic Time ◽  
Free Fall ◽  
Isolated Galaxies ◽  
The Galaxy ◽  
Galaxy Masses

ABSTRACT In simple models of galaxy formation and evolution, star formation is solely regulated by the amount of gas present in the galaxy. However, it has recently been shown that star formation can be suppressed by galactic dynamics in galaxies that contain a dominant spheroidal component and a low gas fraction. This ‘dynamical suppression’ is hypothesized to also contribute to quenching gas-rich galaxies at high redshift, but its impact on the galaxy population at large remains unclear. In this paper, we assess the importance of dynamical suppression in the context of gas regulator models of galaxy evolution through hydrodynamic simulations of isolated galaxies, with gas-to-stellar mass ratios of 0.01–0.20 and a range of galactic gravitational potentials from disc-dominated to spheroidal. Star formation is modelled using a dynamics-dependent efficiency per free-fall time, which depends on the virial parameter of the gas. We find that dynamical suppression becomes more effective at lower gas fractions and quantify its impact on the star formation rate as a function of gas fraction and stellar spheroid mass surface density. We combine the results of our simulations with observed scaling relations that describe the change of galaxy properties across cosmic time, and determine the galaxy mass and redshift range where dynamical suppression may affect the baryon cycle. We predict that the physics of star formation can limit and regulate the baryon cycle at low redshifts (z ≲ 1.4) and high galaxy masses (M* ≳ 3 × 1010 M⊙), where dynamical suppression can drive galaxies off the star formation main sequence.

scholarly journals Theoretical clues about dust accumulation and galaxy obscuration at high and low redshift

2020 ◽  
Vol 499 (2) ◽  
pp. 1701-1720
Author(s):  
Jullian H Barbosa-Santos ◽  
Gastão B Lima Neto ◽  
Amancio C S Friaça
Keyword(s):  
Star Formation ◽  
Galaxy Formation ◽  
Formation Rate ◽  
Cosmic Time ◽  
High Mass ◽  
Lower Efficiency ◽  
James Webb Space Telescope ◽  
The Difference ◽  
Good Tracer ◽  
Formation Systems

ABSTRACT Since the epoch of cosmic star formation peaks at z ∼ 2, most of it is obscured in high-mass galaxies, while in low-mass galaxies, the radiation escapes unobstructed. During the reionization epoch, the presence of evolved, dust obscured galaxies are a challenge to galaxy formation and evolution models. By means of a chemodynamical evolution model, we investigate the star formation and dust production required to build up the bulk of dust in galaxies with initial baryonic mass ranging from 7.5 × 107 to 2.0 × 1012 M⊙. The star formation efficiency was also chosen to represent the star formation rate (SFR) from irregular dwarf to giant elliptical galaxies. We adopted a dust coagulation efficiency from Dwek (Case A) as well as a lower efficiency one (Case B), about five times smaller than Case A. All possible combination of these parameters was computed, summing 40 different scenarios. We find that in high stellar formation systems, the dust accretion in interstellar medium rules over stellar production before the star formation peak, making these systems almost insensible to dust coagulation efficiency. In low star formation systems, the difference between Case A and B lasts longer, mainly in small galaxies. Thus, small irregular galaxies should be the best place to discriminate different dust sources. In our observational sample, taken from the literature, the dust-to-gas ratio tends to be more spread only than dust mass, for both stellar mass and SFR. The dust-to-gas versus dust-to-star diagram is a good tracer for both galaxy and dust evolution, due to the link between gas, star, dust, and SFR. However, the model do not constrain simultaneously all this quantities. The new generation facilities (such as James Webb Space Telescope, Extremely Large Telescope, GMT, and SPICA) will be indispensable to constrain dust formation across the cosmic time.

scholarly journals Discovery of a 12 billion solar mass black hole at redshift 6.3 and its challenge to the black hole/galaxy coevolution at cosmic dawn

2015 ◽  
Vol 11 (S319) ◽  
pp. 80-83 ◽  
Author(s):  
Xue-Bing Wu ◽  
Feige Wang ◽  
Xiaohui Fan ◽  
Weimin Yi ◽  
Wenwen Zuo ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Infrared Spectroscopy ◽  
Galaxy Formation ◽  
Near Infrared ◽  
Host Galaxy ◽  
Black Hole Mass ◽  
Solar Mass ◽  
Massive Black Holes ◽  
Mass Assembly

AbstractThe existence of black holes with masses of about one billion solar masses in quasars at redshifts z > 6 presents significant challenges to theories of the formation and growth of black holes and the black hole/galaxy co-evolution in the early Universe. Here we report a recent discovery of an ultra-luminous quasar at redshift z = 6.30, which has an observed optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. With near-infrared spectroscopy, we obtain a black hole mass of about 12 billion solar masses, which is well consistent with the mass derived by assuming an Eddington-limited accretion. This ultra-luminous quasar with at z > 6 provides a unique laboratory to the study of the mass assembly and galaxy formation around the most massive black holes at cosmic dawn. It raises further challenges to the black hole/galaxy co-evolution in the epoch of cosmic reionization because the black hole needs to grow much faster than the host galaxy.

scholarly journals The ALPINE-ALMA [C II] survey

2020 ◽  
Vol 643 ◽  
pp. A5 ◽  
Author(s):  
M. Dessauges-Zavadsky ◽  
M. Ginolfi ◽  
F. Pozzi ◽  
M. Béthermin ◽  
O. Le Fèvre ◽  
...  
Keyword(s):  
Star Formation ◽  
Rest Frame ◽  
Formation Rate ◽  
Cosmic Time ◽  
Mean Value ◽  
Gas Content ◽  
Molecular Gas ◽  
Massive Galaxies ◽  
Star Forming ◽  
Normal Galaxies

The molecular gas content of normal galaxies at z >  4 is poorly constrained because the commonly used molecular gas tracers become hard to detect at these high redshifts. We use the [C II] 158 μm luminosity, which was recently proposed as a molecular gas tracer, to estimate the molecular gas content in a large sample of main sequence star-forming galaxies at z = 4.4 − 5.9, with a median stellar mass of 109.7 M⊙, drawn from the ALMA Large Program to INvestigate [C II] at Early times survey. The agreement between the molecular gas masses derived from [C II] luminosities, dynamical masses, and rest-frame 850 μm luminosities extrapolated from the rest-frame 158 μm continuum supports [C II] as a reliable tracer of molecular gas in our sample. We find a continuous decline of the molecular gas depletion timescale from z = 0 to z = 5.9, which reaches a mean value of (4.6 ± 0.8) × 108 yr at z ∼ 5.5, only a factor of between two and three shorter than in present-day galaxies. This suggests a mild enhancement of the star formation efficiency toward high redshifts. Our estimates also show that the previously reported rise in the molecular gas fraction flattens off above z ∼ 3.7 to achieve a mean value of 63%±3% over z = 4.4 − 5.9. This redshift evolution of the gas fraction is in line with that of the specific star formation rate. We use multi-epoch abundance-matching to follow the gas fraction evolution across cosmic time of progenitors of z = 0 Milky Way-like galaxies in ∼1013 M⊙ halos and of more massive z = 0 galaxies in ∼1014 M⊙ halos. Interestingly, the former progenitors show a monotonic increase of the gas fraction with redshift, while the latter show a steep rise from z = 0 to z ∼ 2 followed by a constant gas fraction from z ∼ 2 to z = 5.9. We discuss three possible effects, namely outflows, a pause in gas supply, and over-efficient star formation, which may jointly contribute to the gas fraction plateau of the latter massive galaxies.

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