Tracing young SMBHs in the dusty distant universe – a Chandra view of DOGs

2020 ◽  
Vol 15 (S359) ◽  
pp. 17-21
Author(s):  
Karín Menéndez-Delmestre ◽  
Laurie Riguccini ◽  
Ezequiel Treister
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Far Infrared ◽  
Host Galaxy ◽  
X Ray ◽  
Star Forming ◽  
Near Ir ◽  
X Ray Imaging ◽  
Combined Use ◽  
Dusty Galaxies

AbstractThe coexistence of star formation and AGN activity has geared much attention to dusty galaxies at high redshifts, in the interest of understanding the origin of the Magorrian relation observed locally, where the mass of the stellar bulk in a galaxy appears to be tied to the mass of the underlying supermassive black hole. We exploit the combined use of far-infrared (IR) Herschel data and deep Chandra ˜160 ksec depth X-ray imaging of the COSMOS field to probe for AGN signatures in a large sample of >100 Dust-Obscured Galaxies (DOGs). Only a handful (˜20%) present individual X-ray detections pointing to the presence of significant AGN activity, while X-ray stacking analysis on the X-ray undetected DOGs points to a mix between AGN activity and star formation. Together, they are typically found on the main sequence of star-forming galaxies or below it, suggesting that they are either still undergoing significant build up of the stellar bulk or have started quenching. We find only ˜30% (6) Compton-thick AGN candidates (NH > 1024 cm–2), which is the same frequency found within other soft- and hard-X-ray selected AGN populations. This suggests that the large column densities responsible for the obscuration in Compton-thick AGNs must be nuclear and have little to do with the dust obscuration of the host galaxy. We find that DOGs identified to have an AGN share similar near-IR and mid-to-far-IR colors, independently of whether they are individually detected or not in the X-ray. The main difference between the X-ray detected and the X-ray undetected populations appears to be in their redshift distributions, with the X-ray undetected ones being typically found at larger distances. This strongly underlines the critical need for multiwavelength studies in order to obtain a more complete census of the obscured AGN population out to higher redshifts. For more details, we refer the reader to Riguccini et al. (2019).

scholarly journals Redshift measurement through star formation

2019 ◽  
Vol 629 ◽  
pp. A7
Author(s):  
Mikkel O. Lindholmer ◽  
Kevin A. Pimbblet
Keyword(s):  
Star Formation ◽  
Galaxy Clusters ◽  
Main Sequence ◽  
Formation Rate ◽  
Sloan Digital Sky Survey ◽  
X Ray ◽  
Star Forming ◽  
Sky Survey ◽  
The Galaxy ◽  
Galaxy Population

In this work we use the property that, on average, star formation rate increases with redshift for objects with the same mass – the so called galaxy main sequence – to measure the redshift of galaxy clusters. We use the fact that the general galaxy population forms both a quenched and a star-forming sequence, and we locate these ridges in the SFR–M⋆ plane with galaxies taken from the Sloan Digital Sky Survey in discrete redshift bins. We fitted the evolution of the galaxy main sequence with redshift using a new method and then subsequently apply our method to a suite of X-ray selected galaxy clusters in an attempt to create a new distance measurement to clusters based on their galaxy main sequence. We demonstrate that although it is possible in several galaxy clusters to measure the main sequences, the derived distance and redshift from our galaxy main sequence fitting technique has an accuracy of σz = ±0.017 ⋅ (z + 1) and is only accurate up to z ≈ 0.2.

scholarly journals The ALPINE-ALMA [CII] survey

2020 ◽  
Vol 643 ◽  
pp. A8 ◽  
Author(s):  
C. Gruppioni ◽  
M. Béthermin ◽  
F. Loiacono ◽  
O. Le Fèvre ◽  
P. Capak ◽  
...  
Keyword(s):  
Star Formation ◽  
Luminosity Function ◽  
Near Infrared ◽  
Formation Rate ◽  
Ultra Violet ◽  
Far Infrared ◽  
Mass Function ◽  
High Mass ◽  
Near Ir ◽  
Dusty Galaxies

Aims. We present the detailed characterisation of a sample of 56 sources serendipitously detected in ALMA band 7 as part of the ALMA Large Program to INvestigate CII at Early Times (ALPINE). These sources, detected in COSMOS and ECDFS, have been used to derive the total infrared luminosity function (LF) and to estimate the cosmic star formation rate density (SFRD) up to z ≃ 6. Methods. We looked for counterparts of the ALMA sources in all the available multi-wavelength (from HST to VLA) and photometric redshift catalogues. We also made use of deeper UltraVISTA and Spitzer source lists and maps to identify optically dark sources with no matches in the public catalogues. We used the sources with estimated redshifts to derive the 250 μm rest-frame and total infrared (8–1000 μm) LFs from z ≃ 0.5 to 6. Results. Our ALMA blind survey (860 μm flux density range: ∼0.3–12.5 mJy) allows us to further push the study of the nature and evolution of dusty galaxies at high-z, identifying luminous and massive sources to redshifts and faint luminosities never probed before by any far-infrared surveys. The ALPINE data are the first ones to sample the faint end of the infrared LF, showing little evolution from z ≃ 2.5 to z ≃ 6, and a “flat” slope up to the highest redshifts (i.e. 4.5 <  z <  6). The SFRD obtained by integrating the luminosity function remains almost constant between z ≃ 2 and z ≃ 6, and significantly higher than the optical or ultra-violet derivations, showing a significant contribution of dusty galaxies and obscured star formation at high-z. About 14% of all the ALPINE serendipitous continuum sources are found to be optically and near-infrared (near-IR) dark (to a depth Ks ∼ 24.9 mag). Six show a counterpart only in the mid-IR and no HST or near-IR identification, while two are detected as [C II] emitters at z ≃ 5. The six HST+near-IR dark galaxies with mid-IR counterparts are found to contribute about 17% of the total SFRD at z ≃ 5 and to dominate the high-mass end of the stellar mass function at z >  3.

scholarly journals The AGN contribution to the UV–FIR luminosities of interacting galaxies and its role in identifying the main sequence

2020 ◽  
Vol 499 (3) ◽  
pp. 4325-4369
Author(s):  
Andrés F Ramos Padilla ◽  
M L N Ashby ◽  
Howard A Smith ◽  
Juan R Martínez-Galarza ◽  
Aliza G Beverage ◽  
...  
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Spectral Energy Distribution ◽  
Broad Band ◽  
Far Infrared ◽  
Stellar Mass ◽  
Spectral Energy ◽  
Star Forming ◽  
Nuclear Regions ◽  
The Impact

ABSTRACT Emission from active galactic nuclei (AGNs) is known to play an important role in the evolution of many galaxies including luminous and ultraluminous systems (U/LIRGs), as well as merging systems. However, the extent, duration, and exact effects of its influence are still imperfectly understood. To assess the impact of AGNs on interacting systems, we present a spectral energy distribution (SED) analysis of a sample of 189 nearby galaxies. We gather and systematically re-reduce archival broad-band imaging mosaics from the ultraviolet to the far-infrared using data from GALEX, SDSS, 2MASS, IRAS, WISE, Spitzer, and Herschel. We use spectroscopy from Spitzer/IRS to obtain fluxes from fine-structure lines that trace star formation and AGN activity. Utilizing the SED modelling and fitting tool cigale, we derive the physical conditions of the interstellar medium, both in star-forming regions and in nuclear regions dominated by the AGN in these galaxies. We investigate how the star formation rates (SFRs) and the fractional AGN contributions (fAGN) depend on stellar mass, galaxy type, and merger stage. We find that luminous galaxies more massive than about $10^{10} \,\rm {M}_{*}$ are likely to deviate significantly from the conventional galaxy main-sequence relation. Interestingly, infrared AGN luminosity and stellar mass in this set of objects are much tighter than SFR and stellar mass. We find that buried AGNs may occupy a locus between bright starbursts and pure AGNs in the fAGN–[Ne v]/[Ne ii] plane. We identify a modest correlation between fAGN and mergers in their later stages.

scholarly journals Host galaxy properties of radio selected AGN

2013 ◽  
Vol 9 (S304) ◽  
pp. 343-344
Author(s):  
M. Bonzini ◽  
V. Mainieri ◽  
P. Padovani ◽  
K. I. Kellermann ◽  
N. Miller ◽  
...  
Keyword(s):  
Star Formation ◽  
Formation Rate ◽  
Far Infrared ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Star Forming ◽  
Star Formation Activity ◽  
Multi Wavelength ◽  
Deep Sample ◽  
Stellar Masses

AbstractWith the goal of investigating the link between black hole (BH) and star formation (SF) activity, we study a deep sample of radio selected star forming galaxies (SFGs) and active galactic nuclei (AGNs). Using a multi-wavelength approach we characterize their host galaxies properties (stellar masses, optical colors, and morphology). Moreover, comparing the star formation rate derived from the radio and far-infrared luminosity, we found evidences that the main contribution to the radio emission in the radio-quiet AGNs is star-formation activity in their host galaxy.

scholarly journals Disentangling the AGN and star formation connection using XMM-Newton

2018 ◽  
Vol 618 ◽  
pp. A31 ◽  
Author(s):  
V. A. Masoura ◽  
G. Mountrichas ◽  
I. Georgantopoulos ◽  
A. Ruiz ◽  
G. Magdis ◽  
...  
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Learning Algorithm ◽  
Spectral Energy Distribution ◽  
Stellar Mass ◽  
Host Galaxy ◽  
Spectral Energy ◽  
X Ray ◽  
The Galaxy ◽  
Ir Photometry

There is growing evidence supporting the coeval growth of galaxies and their resident super-massive black hole (SMBH). Most studies also claim a correlation between the activity of the SMBH and the star formation of the host galaxy. It is unclear, however, whether this correlation extends to all redshifts and X-ray luminosities. Some studies find a weaker dependence at lower luminosities and/or a suppression of the star formation at high luminosities. We here use data from the X-ATLAS and XMM-XXL North fields and compile the largest X-ray sample up to date to investigate how X-ray selected AGN affect the star formation of their host galaxies in a wide redshift and luminosity baseline of 0.03 < z < 3 and log LX(2−10 keV) = (41−45.5) erg s−1. Our sample consists of 3336 AGN. 1872 of our sources have spectroscopic redshifts. For the remaining sources we calculate photometric redshifts using TPZ, a machine-learning algorithm. We estimate stellar masses (M⋆) and star formation rates (SFRs) by applying spectral energy distribution fitting through the CIGALE code, using optical, near-IR, and mid-IR photometry (SDSS, VISTA, and WISE). Of our sources, 608 also have far-IR photometry (Herschel). We use these sources to calibrate the SFR calculations of our remaining X-ray sample. Our results show a correlation between the X-ray luminosity (LX) and the SFR of the host galaxy at all redshifts and luminosities spanned by our sample. We also find a dependence of the specific SFR (sSFR) on redshift, while there are indications that the X-ray luminosity enhances the sSFR even at low redshifts. We then disentangle the effects of stellar mass and redshift on the SFR and again study its dependence on the X-ray luminosity. Towards this end, we estimate the SFR of main-sequence galaxies that have the same stellar mass and redshift as our X-ray AGN and compare them with the SFR of our X-ray AGN. Our analysis reveals that the AGN enhances the star formation of its host galaxy when the galaxy lies below the main sequence and quenches the star formation of the galaxy it lives in when the host lies above the main sequence. Therefore, the effect of AGN on the SFR of the host galaxy depends on the location of the galaxy relative to the main sequence.

scholarly journals Starbursts in and out of the star-formation main sequence

2018 ◽  
Vol 616 ◽  
pp. A110 ◽  
Author(s):  
D. Elbaz ◽  
R. Leiton ◽  
N. Nagar ◽  
K. Okumura ◽  
M. Franco ◽  
...  
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Near Infrared ◽  
Compact Star ◽  
Far Infrared ◽  
High Mass ◽  
Star Forming ◽  
Stellar Component ◽  
Public Data ◽  
Gas Fractions

Aims. We use high-resolution continuum images obtained with the Atacama Large Millimeter Array (ALMA) to probe the surface density of star formation in z ~ 2 galaxies and study the different physical properties between galaxies within and above the star-formation main sequence of galaxies. Methods. We use ALMA images at 870 μm with 0.2 arcsec resolution in order to resolve star formation in a sample of eight star-forming galaxies at z ~ 2 selected among the most massive Herschel galaxies in the GOODS-South field. This sample is supplemented with eleven galaxies from the public data of the 1.3 mm survey of the Hubble Ultra-Deep Field, HUDF. We derive dust and gas masses for the galaxies, compute their depletion times and gas fractions, and study the relative distributions of rest-frame ultraviolet (UV) and far-infrared (FIR) light. Results. ALMA reveals systematically dense concentrations of dusty star formation close to the center of the stellar component of the galaxies. We identify two different starburst regimes: (i) the classical population of starbursts located above the SFR-M⋆ main sequence, with enhanced gas fractions and short depletion times and (ii) a sub-population of galaxies located within the scatter of the main sequence that experience compact star formation with depletion timescales typical of starbursts of ~150 Myr. In both starburst populations, the FIR and UV are distributed in distinct regions and dust-corrected star formation rates (SFRs) estimated using UV-optical-near-infrared data alone underestimate the total SFR. Starbursts hidden in the main sequence show instead the lowest gas fractions of our sample and could represent the last stage of star formation prior to passivization. Being Herschel-selected, these main sequence galaxies are located in the high-mass end of the main sequence, hence we do not know whether these “starbursts hidden in the main sequence” also exist below 1011 M⊙. Active galactic nuclei (AGNs) are found to be ubiquitous in these compact starbursts, suggesting that the triggering mechanism also feeds the central black hole or that the active nucleus triggers star formation.

scholarly journals GRB host galaxies: theoretical investigation

2011 ◽  
Vol 7 (S279) ◽  
pp. 353-354
Author(s):  
Jirong Mao
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Galaxy Evolution ◽  
Gamma Ray ◽  
Dark Matter Halo ◽  
Host Galaxy ◽  
Host Galaxies ◽  
X Ray ◽  
Star Forming ◽  
Stellar Masses

AbstractLong gamma-ray bursts (GRBs) can be linked to the massive stars and their host galaxies are assumed to be the star-forming galaxies within small dark matter halos. We apply a galaxy evolution model, in which the star formation process inside the virialized dark matter halo at a given redshift is achieved. The star formation rates (SFRs) in the GRB host galaxies at different redshifts can be derived from our model. The related stellar masses, luminosities, and metalicities of these GRB host galaxies are estimated. We also calculate the X-ray and optical absorption of GRB afterglow emission. At higher redshift, the SFR of host galaxy is stronger, and the absorption in the X-ray and optical bands of GRB afterglow is stronger, when the dust and metal components are locally released, surrounding the GRB environment. These model predictions are compared with some observational data as well.

scholarly journals Main sequence of star forming galaxies beyond the Herschel confusion limit

2018 ◽  
Vol 615 ◽  
pp. A146 ◽  
Author(s):  
W. J. Pearson ◽  
L. Wang ◽  
P. D. Hurley ◽  
K. Małek ◽  
V. Buat ◽  
...  
Keyword(s):  
Star Formation ◽  
Power Law ◽  
Main Sequence ◽  
Spectral Energy Distribution ◽  
Far Infrared ◽  
Star Formation History ◽  
High Mass ◽  
Spectral Energy ◽  
Star Forming ◽  
Confusion Limit

Context. Deep far-infrared (FIR) cosmological surveys are known to be affected by source confusion, causing issues when examining the main sequence (MS) of star forming galaxies. In the past this has typically been partially tackled by the use of stacking. However, stacking only provides the average properties of the objects in the stack. Aims. This work aims to trace the MS over 0.2 ≤ z < 6.0 using the latest de-blended Herschel photometry, which reaches ≈10 times deeper than the 5σ confusion limit in SPIRE. This provides more reliable star formation rates (SFRs), especially for the fainter galaxies, and hence a more reliable MS. Methods. We built a pipeline that uses the spectral energy distribution (SED) modelling and fitting tool CIGALE to generate flux density priors in the Herschel SPIRE bands. These priors were then fed into the de-blending tool XID+ to extract flux densities from the SPIRE maps. In the final step, multi-wavelength data were combined with the extracted SPIRE flux densities to constrain SEDs and provide stellar mass (M⋆) and SFRs. These M⋆ and SFRs were then used to populate the SFR-M⋆ plane over 0.2 ≤ z < 6.0. Results. No significant evidence of a high-mass turn-over was found; the best fit is thus a simple two-parameter power law of the form log(SFR) = α[log(M⋆) − 10.5] + β. The normalisation of the power law increases with redshift, rapidly at z ≲ 1.8, from 0.58 ± 0.09 at z ≈ 0.37 to 1.31 ± 0.08 at z ≈ 1.8. The slope is also found to increase with redshift, perhaps with an excess around 1.8 ≤ z < 2.9. Conclusions. The increasing slope indicates that galaxies become more self-similar as redshift increases. This implies that the specific SFR of high-mass galaxies increases with redshift, from 0.2 to 6.0, becoming closer to that of low-mass galaxies. The excess in the slope at 1.8 ≤ z < 2.9, if present, coincides with the peak of the cosmic star formation history.

scholarly journals Narrow-band Hα imaging of nearby Wolf–Rayet galaxies

2019 ◽  
Vol 490 (3) ◽  
pp. 3448-3453
Author(s):  
A Paswan ◽  
Kanak Saha ◽  
A Omar
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Narrow Band ◽  
Far Infrared ◽  
Infrared Excess ◽  
Nearby Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
Far Ultraviolet ◽  
First Time

ABSTRACT We present narrow-band Hα imaging of nearby Wolf–Rayet (WR) galaxies known as a subset of starburst galaxies. The Hα images have been used to show morphology of star-forming regions in galaxies, which leads to speculate that the studied galaxies have most likely experienced merger or interaction with low luminous dwarf galaxies or H i clouds. We further derive the Hα-based star formation rates (SFRs) in galaxies using our Hα observations. These SFRs are well correlated with SFRs derived using other indicators at far-ultraviolet, far-infrared, and 1.4-GHz radio wavebands. It is noticed that the infrared excess (IRX) method gives the best SFR estimates, consistent with different models predication. These models also predict that the sample galaxies have probably gone through a continuous star formation at least for 1 Gyr over which the recent (&lt;10 Myr) star formation has taken place in WR phase. This study presents main-sequence (MS) relation for nearby WR galaxies for the first time. This derived MS relation is found to be similar to previously known MS relation for normal nearby star-forming galaxies, suggesting that WR systems evolve in a similar fashion as normal star-forming galaxies evolve.

scholarly journals Detection of an ionized gas outflow in the extreme UV-luminous star-forming galaxy BOSS-EUVLG1 at z = 2.47

2021 ◽  
Vol 647 ◽  
pp. A133
Author(s):  
J. Álvarez-Márquez ◽  
R. Marques-Chaves ◽  
L. Colina ◽  
I. Pérez-Fournon
Keyword(s):  
Star Formation ◽  
Host Galaxy ◽  
Ionized Gas ◽  
Mass Rate ◽  
X Ray ◽  
Star Forming ◽  
High Ionization ◽  
Relevant Role ◽  
Extreme Uv ◽  
Low Mass

BOSS-EUVLG1 is the most ultraviolet (UV) and Lyα luminous galaxy to be going through a very active starburst phase detected thus far in the Universe. It is forming stars at a rate of 955 ± 118 M⊙ yr−1. We report the detection of a broad Hα component carrying 25% of the total Hα flux. The broad Hα line traces a fast and massive ionized gas outflow characterized by a total mass, log(Mout[M⊙]), of 7.94 ± 0.15, along with an outflowing velocity (Vout) of 573 ± 151 km s−1 and an outflowing mass rate (Ṁout) of 44 ± 20 M⊙ yr−1. The presence of the outflow in BOSS-EUVLG1 is also supported by the identification of blueshifted UV absorption lines in low and high ionization states. The energy involved in the Hα outflow can be explained by the ongoing star formation, without the need for an active galactic nucleus to be included in the scenario. The derived low mass-loading factor (η = 0.05 ± 0.03) indicates that, although it is massive, this phase of the outflow cannot be relevant for the quenching of the star formation, namely, the negative feedback. In addition, only a small fraction (≤15%) of the ionized outflowing material with velocities above 372 km s−1 has the capacity to escape the gravitational potential and to enrich the surrounding circumgalactic medium at distances above several tens of kpc. The ionized phase of the outflow does not carry sufficient mass or energy to play a relevant role in the evolution of the host galaxy nor in the enrichment of the intergalactic medium. As predicted by some recent simulations, other phases of the outflow could be responsible for most of the outflow energy and mass in the form of hot X-ray emitting gas. The expected emission of the extended X-ray emitting halo associated with the outflow in BOSS-EUVLG1 and similar galaxies could be detected with the future ATHENA X-ray observatory, however, there are no methods at present that would assist in their spatial resolution.

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