Multiwavelength morphological study of active galaxies

AbstractStudying the morphology of a large sample of active galaxies at different wavelengths and comparing it with active galactic nuclei (AGN) properties, such as black hole mass (MBH) and Eddington ratio (λEdd), can help us in understanding better the connection between AGN and their host galaxies and the role of nuclear activity in galaxy formation and evolution. By using the BAT-SWIFT hard X-ray public data and by extracting those parameters measured for AGN and by using other public catalogues for parameters such as stellar mass (M*), star formation rate (SFR), bolometric luminosity (Lbol), etc., we studied the multiwavelength morphological properties of host galaxies of ultra-hard X-ray detected AGN and their correlation with other AGN properties. We found that ultra hard X-ray detected AGN can be hosted by all morphological types, but in larger fractions (42%) they seem to be hosted by spirals in optical, to be quiet in radio, and to have compact morphologies in X-rays. When comparing morphologies with other galaxy properties, we found that ultra hard X-ray detected AGN follow previously obtained relations. On the SFR vs. stellar mass diagram, we found that although the majority of sources are located below the main sequence (MS) of star formation (SF), still non-negligible number of sources, with diverse morphologies, is located on and/or above the MS, suggesting that AGN feedback might have more complex influence on the SF in galaxies than simply quenching it, as it was suggested in some of previous studies.

Download Full-text

Ultraluminous X-ray source populations in the Chandra Source Catalog 2.0

Proceedings of the International Astronomical Union ◽

10.1017/s1743921318008086 ◽

2018 ◽

Vol 14 (S346) ◽

pp. 247-251

Author(s):

Konstantinos Kovlakas ◽

Andreas Zezas ◽

Jeff J. Andrews ◽

Antara Basu-Zych ◽

Tassos Fragos ◽

...

Keyword(s):

Star Formation ◽

Star Formation Rate ◽

Formation Rate ◽

Stellar Mass ◽

Compact Objects ◽

Host Galaxies ◽

X Ray ◽

Multi Wavelength ◽

Accretion Physics ◽

Stellar Properties

Abstract. The nature and evolution of ultraluminous X-ray sources (ULXs) is an open problem in astrophysics. They challenge our current understanding of stellar compact objects and accretion physics. The recent discovery of pulsar ULXs further demonstrates the importance of this intriguing and rare class of objects.In order to overcome the difficulties of directly studying the optical associations of ULXs, we generally resort in statistical studies of the stellar properties of their host galaxies. We present the largest such study based on the combination of Chandra archival data with the most complete galaxy catalog of the Local Universe. Incorporating robust distances and stellar population parameters based on associated multi-wavelength information, and we explore the association of ULXs with galaxies in the (star formation rate, stellar mass, metallicity) space.We confirm the known correlation with morphology, star formation rate and stellar mass, while we find an excess of ULXs in dwarf galaxies, indicating dependence on age and metallicity.

Download Full-text

Clustering dependence of Chandra COSMOS Legacy AGN on host galaxy properties

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320002987 ◽

2019 ◽

Vol 15 (S356) ◽

pp. 226-226

Author(s):

Viola Allevato

Keyword(s):

Dark Matter ◽

Formation Rate ◽

Stellar Mass ◽

Active Galaxies ◽

Host Galaxy ◽

Mass Star ◽

Mass Relation ◽

Dark Matter Halos ◽

X Ray

AbstractThe presence of a super massive BH in almost all galaxies in the Universe is an accepted paradigm in astronomy. How these BHs form and how they co-evolve with the host galaxy is one of the most intriguing unanswered problems in modern Cosmology and of extreme relevance to understand the issue of galaxy formation. Clustering measurements can powerfully test theoretical model predictions of BH triggering scenarios and put constraints on the typical environment where AGN live in, through the connection with their host dark matter halos. In this talk, I will present some recent results on the AGN clustering dependence on host galaxy properties, such as galaxy stellar mass, star formation rate and specific BH accretion rate, based on X-ray selected Chandra COSMOS Legacy Type 2 AGN. We found no significant AGN clustering dependence on galaxy stellar mass and specif BHAR for Type 2 COSMOS AGN at mean z ∼ 1.1, with a stellar - halo mass relation flatter than predicted for non active galaxies in the Mstar range probed by our sample. We also observed a negative clustering dependence on SFR, with AGN hosting halo mass increasing with decreasing SFR. Mock catalogs of active galaxies in hosting dark matter halos with logMh[Msun] > 12.5, matched to have the same X-ray luminosity, stellar mass and BHAR of COSMOS AGN predict the observed Mstar - Mh, BHAR - Mh and SFR-Mh relations, at z ∼ 1.

Download Full-text

Testing galaxy formation simulations with damped Lyman-α abundance and metallicity evolution

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa056 ◽

2020 ◽

Vol 492 (2) ◽

pp. 2835-2846 ◽

Cited By ~ 4

Author(s):

Sultan Hassan ◽

Kristian Finlator ◽

Romeel Davé ◽

Christopher W Churchill ◽

J Xavier Prochaska

Keyword(s):

Star Formation ◽

Galaxy Formation ◽

Star Formation Rate ◽

Initial Conditions ◽

Mass Density ◽

Formation Rate ◽

Thomson Scattering ◽

Stellar Mass ◽

Rate Functions ◽

Metallicity Distribution

ABSTRACT We examine the properties of damped Lyman-α absorbers (DLAs) emerging from a single set of cosmological initial conditions in two state-of-the-art cosmological hydrodynamic simulations: simba and technicolor dawn. The former includes star formation and black hole feedback treatments that yield a good match with low-redshift galaxy properties, while the latter uses multifrequency radiative transfer to model an inhomogeneous ultraviolet background (UVB) self-consistently and is calibrated to match the Thomson scattering optical depth, UVB amplitude, and Ly α forest mean transmission at z > 5. Both simulations are in reasonable agreement with the measured stellar mass and star formation rate functions at z ≥ 3, and both reproduce the observed neutral hydrogen cosmological mass density, $\Omega _{\rm H\, \small{I}}(z)$. However, the DLA abundance and metallicity distribution are sensitive to the galactic outflows’ feedback and the UVB amplitude. Adopting a strong UVB and/or slow outflows underproduces the observed DLA abundance, but yields broad agreement with the observed DLA metallicity distribution. By contrast, faster outflows eject metals to larger distances, yielding more metal-rich DLAs whose observational selection may be more sensitive to dust bias. The DLA metallicity distribution in models adopting an H2-regulated star formation recipe includes a tail extending to [M/H] ≪ −3, lower than any DLA observed to date, owing to curtailed star formation in low-metallicity galaxies. Our results show that DLA observations play an important role in constraining key physical ingredients in galaxy formation models, complementing traditional ensemble statistics such as the stellar mass and star formation rate functions.

Download Full-text

The star formation properties of the observed and simulated AGN Universe: BAT versus EAGLE

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2414 ◽

2020 ◽

Vol 498 (2) ◽

pp. 2323-2338

Author(s):

Thomas M Jackson ◽

D J Rosario ◽

D M Alexander ◽

J Scholtz ◽

Stuart McAlpine ◽

...

Keyword(s):

Star Formation ◽

High Redshift ◽

Spectral Energy Distribution ◽

Formation Rate ◽

Host Galaxy ◽

Spectral Energy ◽

Host Galaxies ◽

X Ray ◽

Two Samples ◽

Stellar Masses

ABSTRACT In this paper, we present data from 72 low-redshift, hard X-ray selected active galactic nucleus (AGN) taken from the Swift–BAT 58 month catalogue. We utilize spectral energy distribution fitting to the optical to infrared photometry in order to estimate host galaxy properties. We compare this observational sample to a volume- and flux-matched sample of AGN from the Evolution and Assembly of GaLaxies and their Environments (EAGLE) hydrodynamical simulations in order to verify how accurately the simulations can reproduce observed AGN host galaxy properties. After correcting for the known +0.2 dex offset in the SFRs between EAGLE and previous observations, we find agreement in the star formation rate (SFR) and X-ray luminosity distributions; however, we find that the stellar masses in EAGLE are 0.2–0.4 dex greater than the observational sample, which consequently leads to lower specific star formation rates (sSFRs). We compare these results to our previous study at high redshift, finding agreement in both the observations and simulations, whereby the widths of sSFR distributions are similar (∼0.4–0.6 dex) and the median of the SFR distributions lie below the star-forming main sequence by ∼0.3–0.5 dex across all samples. We also use EAGLE to select a sample of AGN host galaxies at high and low redshift and follow their characteristic evolution from z = 8 to z = 0. We find similar behaviour between these two samples, whereby star formation is quenched when the black hole goes through its phase of most rapid growth. Utilizing EAGLE we find that 23 per cent of AGN selected at z ∼ 0 are also AGN at high redshift, and that their host galaxies are among the most massive objects in the simulation. Overall, we find EAGLE reproduces the observations well, with some minor inconsistencies (∼0.2 dex in stellar masses and ∼0.4 dex in sSFRs).

Download Full-text

ENVIRONMENTAL DEPENDENCE OF AGE, STELLAR MASS, STAR FORMATION RATE AND STELLAR VELOCITY DISPERSION OF ACTIVE GALACTIC NUCLEUS HOST GALAXIES

Revista Mexicana de Astronomía y Astrofísica ◽

10.22201/ia.01851101p.2021.57.01.11 ◽

2021 ◽

Vol 57 (1) ◽

pp. 157-166

Author(s):

Xin-Fa Deng ◽

Xiao-Qing Wen

Keyword(s):

Star Formation ◽

Active Galactic Nucleus ◽

Velocity Dispersion ◽

Star Formation Rate ◽

Formation Rate ◽

Stellar Mass ◽

Apparent Magnitude ◽

Host Galaxies ◽

Stellar Velocity ◽

Environmental Dependence

Using the apparent-magnitude limited active galactic nucleus (AGN) host galaxy sample of the Sloan Digital Sky Survey Data Release 12 (SDSS DR12), we investigate the environmental dependence of age, stellar mass, the star formation rate (SFR) and stellar velocity dispersion of AGN host galaxies. We divide the whole apparent-magnitude limited AGN sample into many subsamples with a redshift binning size of Δz = 0.01, and analyse the environmental dependence of these galaxy properties of subsamples in each redshift bin. It turns out that these parameters of AGN host galaxies seemingly only have a weak environmental dependence.

Download Full-text

The dependence of AGN activity on environment in SDSS

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz1706 ◽

2019 ◽

Vol 488 (1) ◽

pp. 89-98 ◽

Cited By ~ 6

Author(s):

Zhong-yi Man ◽

Ying-jie Peng ◽

Xu Kong ◽

Ke-xin Guo ◽

Cheng-peng Zhang ◽

...

Keyword(s):

Star Formation ◽

Formation Rate ◽

Stellar Mass ◽

Minor Role ◽

Host Galaxies ◽

Star Forming ◽

Secular Evolution ◽

Intrinsic Correlation ◽

Merger Rate ◽

A Minor

ABSTRACT Environment is one of the key external drivers of the galaxies, while active galactic nucleus (AGN) is one of the key internal drivers. Both of them play fundamental roles in regulating the formation and evolution of galaxies. We explore the interrelationship between environment and AGN in SDSS. At a given stellar mass, the specific star formation rate distribution of the AGN host galaxies remains unchanged with overdensity, with the peak of the distribution around the Green Valley. We show that, at a given stellar mass, the AGN fraction that has been commonly used in previous studies (defined as the number of AGNs relative to all galaxies including passive and star forming ones) does decrease with increasing overdensity for satellites. This is largely due to the fact that the fraction of passive galaxies strongly depends on environment. In order to investigate the intrinsic correlation between AGN and environment, especially under the assumption that AGN feedback is responsible for star formation quenching, the AGN fraction should be defined as the number of AGNs relative to the star-forming galaxies only. With the new definition, we find little dependence of AGN fraction on overdensity, central/satellite, and group halo mass. There is only marginal evidence that AGN may prefer denser regions, which is possibly due to more frequent interaction of galaxies or higher merger rate in groups. Our results support the scenario that internal secular evolution is the predominant mechanism of triggering AGN activity, while external environment related processes only play a minor role.

Download Full-text

The roles of atomic and molecular gas on the redshift evolution of star formation and metallicity in galaxy formation models

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313001208 ◽

2012 ◽

Vol 8 (S292) ◽

pp. 245-245

Author(s):

Jian Fu ◽

Guinevere Kauffmann

Keyword(s):

Star Formation ◽

Galaxy Formation ◽

Time Scale ◽

High Redshift ◽

Formation Rate ◽

Stellar Mass ◽

Formation Time ◽

Model Parameters ◽

Molecular Gas ◽

Mass Relation

AbstractWe study the redshift evolution of neutral and molecular gas in the interstellar medium with the results from semi-analytic models of galaxy formation and evolution, which track the cold gas related physical processes in radially resolved galaxy disks. Two kinds of prescriptions are adopted to describe the conversion between molecular and neutral gas in the ISM: one is related to the gas surface density and gas metallicity based on the model results by Krumholz, Mckee & Tumlinson; the other is related the pressure of ISM. We try four types of star formation laws in the models to study the effect of the molecular gas component and the star formation time scale on the model results, and find that the H2 dependent star formation rate with constant star formation efficiency is the preferred star formation law. We run the models based on both Millennium and Millennium II Simulation haloes, and the model parameters are adjusted to fit the observations at z = 0 from THINGS/HERACLES and ALFALFA/COLD GASS. We give predictions for the redshift evolution of cosmic star formation density, H2 to HI cosmic ratios, gas to star mass ratios and gas metallicity vs stellar mass relation. Based on the model results, we find that: (i) the difference in the H2 to HI ratio at z > 3 between the two H2 fraction prescriptions can help future observations to test which prescription is better; (ii) a constant redshift independent star formation time scale will postpone the star formation processes at high redshift and cause obvious redshift evolution for the relation between gas metallicity and stellar mass in galaxies at z < 3.

Download Full-text

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

Astronomy and Astrophysics ◽

10.1051/0004-6361/201628141 ◽

2017 ◽

Vol 602 ◽

pp. A35 ◽

Cited By ~ 19

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.

Download Full-text

Probing the building blocks of galaxies: Sub-galactic scaling relations between X-ray luminosity, SFR and stellar mass

Proceedings of the International Astronomical Union ◽

10.1017/s1743921319002539 ◽

2019 ◽

Vol 15 (S341) ◽

pp. 162-166

Author(s):

K. Kouroumpatzakis ◽

A. Zezas ◽

P. H. Sell ◽

P. Bonfini ◽

M. L. N. Ashby ◽

...

Keyword(s):

Star Formation ◽

Formation Rate ◽

Building Blocks ◽

Stellar Mass ◽

High Mass ◽

Scaling Relations ◽

Local Universe ◽

X Ray ◽

Star Formation Activity ◽

X Ray Binaries

AbstractIt is well known that X-ray luminosity (Lx) originating from high mass X-ray binaries (HMXBs) is tightly correlated with the host galaxy’s star formation rate (SFR). We explore this connection using a sample representative of the star-formation activity in the local Universe (Star-Formation Reference Survey; SFRS) along with a comprehensive set of star-formation (radio, FIR, 24μm, 8 μm, Hα, UV, SED fitting) and stellar mass (K-band, 3.6 μm, SED fitting) indicators, and Chandra observations. We investigate the Lx–SFR and Lx– stellar mass (M*) scaling relations down to sub-galactic scales of ∼lkpc2. This way we extend these relations to extremely low SFR (∼10−6M⊙.yr−1) and M* (∼104M⊙). We also quantify their scatter and their dependence on the age of the local stellar populations as inferred from the different age sensitive SFR indicators. These results are particularly important for setting the benchmark for the formation of X-ray binaries in vigorous, but low SFR objects such as galaxies in the early Universe.

Download Full-text

Intermediate-mass black hole growth and feedback in dwarf galaxies at high redshifts

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz1616 ◽

2019 ◽

Vol 487 (4) ◽

pp. 5549-5563 ◽

Cited By ~ 8

Author(s):

Paramita Barai ◽

Elisabete M de Gouveia Dal Pino

Keyword(s):

Black Holes ◽

Star Formation ◽

Cold Dark Matter ◽

Dwarf Galaxies ◽

Formation Rate ◽

Mass Range ◽

Stellar Mass ◽

Host Galaxies ◽

Intermediate Mass ◽

Hydrodynamical Simulations

Abstract Intermediate-mass black holes (IMBHs; masses between $100\rm{\, and \,}10^{6} \, \mathrm{M}_{\odot }$) historically comprise of an elusive population compared to stellar-mass and supermassive black holes (BHs). Recently, IMBHs have started to be observed at the centres of low-mass galaxies. We perform cosmological hydrodynamical simulations of $(2 \, h^{-1} ~ {\rm Mpc})^3$ comoving boxes and investigate the growth and feedback of central IMBHs in dwarf galaxies (DGs). The earliest BHs appear at z ∼ 18–25 and grow thereafter by accreting gas and by merger with other BHs. We find that, starting from $10^{2} \, \mathrm{M}_{\odot }$, it is possible to build up IMBHs of a few$\times 10^{5}\!-\!10^{6} \, \mathrm{M}_{\odot }$ by z = 5, when the BHs are seeded in haloes less massive than $4 \times 10^{7} \, \mathrm{M}_{\odot }$. The BH accretion rates increase with time and reach $\dot{M}_{\rm BH} = (0.2\!-\!0.8) \dot{M}_{\rm Edd}$ for the massive IMBHs by z = 4. The star formation rate density (SFRD) evolution of the DGs (stellar mass $10^{5}\!-\!10^{8} \, \mathrm{M}_{\odot }$) has a peak plateau between z = 4 and 6. Star formation is quenched between z = 9 and 4. The SFRD is reduced by factors up to 3 when the BHs have grown to a few times $10^5 \, \mathrm{M}_{\odot }$. Even in the presence of stronger supernova (SN)-driven mass ejection, the BHs continue to grow up to z ∼ 6, sustained by gas inflows driven by galaxy mergers and interactions in a cosmological environment. Our conclusions, based on numerical simulation results, support the scenario that early feedback from IMBHs in gas-rich DGs at z = 5–8 can potentially solve several anomalies in the DG mass range within the concordance Λ cold dark matter (ΛCDM) cosmological scenario (Silk 2017). Our results suggest that IMBHs at DG centres grow faster than their host galaxies in the early Universe, and the resulting BH feedback turns the DGs and the BHs dormant.

Download Full-text