Context. Ionized outflows, revealed by broad asymmetric wings of the O III λ5007 line, are commonly observed in active galactic nuclei (AGN) but the low intrinsic spatial resolution of the ...observations has generally prevented a detailed characterization of their properties. The MAGNUM survey aims at overcoming these limitations by focusing on the nearest AGN, including NGC 1365, a nearby Seyfert galaxy (D ∼ 17 Mpc), hosting a low-luminosity active nucleus (Lbol ∼ 2 × 1043 erg s−1). Aims. We want to obtain a detailed picture of the ionized gas in the central ∼5 kpc of NGC 1365 in terms of physical properties, kinematics, and ionization mechanisms. We also aim to characterize the warm ionized outflow as a function of distance from the nucleus and its relation with the nuclear X-ray wind. Methods. We employed optical integral-field spectroscopic observations from VLT/MUSE to investigate the warm ionized gas and Chandra ACIS-S X-ray data for the hot highly-ionized phase. We obtained flux, kinematic, and diagnostic maps of the optical emission lines, which we used to disentangle outflows from gravitational motions in the disk and measure the gas properties down to a spatial resolution of ∼70 pc. We then performed imaging spectroscopy on Chandra ACIS-S data guided by the matching with MUSE maps. Results. The O III emission mostly traces a kpc-scale biconical outflow ionized by the AGN having velocities up to ∼200 km s−1. Hα emission traces instead star formation in a circumnuclear ring and along the bar, where we detect non-circular streaming gas motions. Soft X-rays are predominantly due to thermal emission from the star-forming regions, but we manage to isolate the AGN photoionized component which nicely matches the O III emission. The mass outflow rate of the extended ionized outflow is similar to that of the nuclear X-ray wind and then decreases with radius, implying that the outflow either slows down or that the AGN activity has recently increased. However, the hard X-ray emission from the circumnuclear ring suggests that star formation might in principle contribute to the outflow. The integrated mass outflow rate, kinetic energy rate, and outflow velocity are broadly consistent with the typical relations observed in more luminous AGN.
Supermassive black holes (SMBHs) and their host galaxies are generally thought to coevolve, so that the SMBH achieves up to about 0.2 to 0.5% of the host galaxy mass in the present day. The radiation ...emitted from the growing SMBH is expected to affect star formation throughout the host galaxy. The relevance of this scenario at early cosmic epochs is not yet established. We present spectroscopic observations of a galaxy at redshift z = 3.328, which hosts an actively accreting, extremely massive BH, in its final stages of growth. The SMBH mass is roughly one-tenth the mass of the entire host galaxy, suggesting that it has grown much more efficiently than the host, contrary to models of synchronized coevolution. The host galaxy is forming stars at an intense rate, despite the presence of a SMBH-driven gas outflow.
Cosmic Evolution of Gas and Star Formation Scoville, Nick; Faisst, Andreas; Weaver, John ...
Astrophysical journal/The Astrophysical journal,
02/2023, Volume:
943, Issue:
2
Journal Article
Peer reviewed
Open access
Abstract
Atacama Large Millimeter/submillimeter Array (ALMA) observations of the long-wavelength dust continuum are used to estimate the gas masses in a sample of 708 star-forming galaxies at
z
= ...0.3−4.5. We determine the dependence of gas masses and star formation efficiencies (SFEs; SFR per unit gas mass) on redshift (z),
M
*
, and star formation rate (SFR) relative to the main sequence (MS). We find that 70% of the increase in SFRs of the MS is due to the increased gas masses at earlier epochs, while 30% is due to increased efficiency of star formation (SF). For galaxies above the MS this is reversed—with 70% of the increased SFR relative to the MS being due to elevated SFEs. Thus, the major evolution of star formation activity at early epochs is driven by increased gas masses, while the starburst activity taking galaxies above the MS is due to enhanced triggering of star formation (likely due to galactic merging). The interstellar gas peaks at
z
= 2 and dominates the stellar mass down to
z
= 1.2. Accretion rates needed to maintain continuity of the MS evolution reach >100
M
⊙
yr
−1
at
z
> 2. The galactic gas contents are likely the driving determinant for both the rise in SF and AGN activity from
z
= 5 to their peak at
z
= 2 and subsequent fall at lower
z
. We suggest that for self-gravitating clouds with supersonic turbulence, cloud collisions and the filamentary structure of the clouds regulate the star formation activity.
Crossing the Rubicon of Reionization with z ∼ 5 QSOs Grazian, Andrea; Boutsia, Konstantina; Giallongo, Emanuele ...
Astrophysical journal/The Astrophysical journal,
09/2023, Volume:
955, Issue:
1
Journal Article
Peer reviewed
Open access
Abstract
One of the key open questions in cosmology is the nature of sources that completed cosmological hydrogen reionization at
z
∼ 5.2. High-
z
primeval galaxies have been long considered the main ...drivers of reionization, with a minor role played by high-
z
active galactic nuclei (AGN). However, in order to confirm this scenario, it is fundamental to measure the photoionization rate produced by active SMBHs close to the Epoch of Reionization. Given the pivotal role played by spectroscopically complete observations of high-
z
QSOs, in this paper we present the first results of the RUBICON (Reionizing the Universe with Bright Cosmological Nuclei) survey. It consists of a color-selected sample of bona fide
z
∼ 5 QSO candidates from the Hyper Suprime-Cam Subaru Strategic Survey. Our QSO candidates have been validated both by photometric redshifts based on spectral energy distribution fitting and by spectroscopic redshifts, confirming that they lie at 4.5 <
z
spec
< 5.2. A relatively high space density of QSOs (Φ ∼ 1.4 × 10
−8
c Mpc
−3
) is thus confirmed at
z
∼ 5 and
M
1450
∼ −27, consistent with a pure density evolution of the AGN luminosity function from
z
= 4 to
z
= 5, with a mild density evolution rate of 0.25 dex. This indicates that AGN could play a nonnegligible role in cosmic reionization. The Rubicon of reionization has been crossed.
Abstract
A large fraction of the accreting supermassive black hole population is shrouded by copious amounts of gas and dust, particularly in the distant (
z
≳ 1) universe. While much of the ...obscuration is attributed to a parsec-scale torus, there is a known contribution from the larger-scale host galaxy. Using JWST/NIRCam imaging from the COSMOS-Web survey, we probe the galaxy-wide dust distribution in X-ray selected active galactic nuclei (AGNs) up to
z
∼ 2. Here, we focus on a sample of three AGNs with their host galaxies exhibiting prominent dust lanes, potentially due to their edge-on alignment. These represent 27% (3 out of 11 with early NIRCam data) of the heavily obscured (
N
H
> 10
23
cm
−2
) AGN population. With limited signs of a central AGN in the optical and near-infrared, the NIRCam images are used to produce reddening maps
E
(
B
−
V
) of the host galaxies. We compare the mean central value of
E
(
B
−
V
) to the X-ray obscuring column density along the line of sight to the AGN (
N
H
∼ 10
23−23.5
cm
−2
). We find that the extinction due to the host galaxy is present (0.6 ≲
E
(
B
−
V
) ≲ 0.9; 1.9 ≲
A
V
≲ 2.8) and significantly contributes to the X-ray obscuration at a level of
N
H
∼ 10
22.5
cm
−2
assuming an SMC gas-to-dust ratio that amounts to ≲30% of the total obscuring column density. These early results, including three additional cases from CEERS, demonstrate the ability to resolve such dust structures with JWST and separate the different circumnuclear and galaxy-scale obscuring structures.
The mid-infrared-to-ultraviolet (0.1–10 μm) spectral energy distribution (SED) shapes of 407 X-ray-selected radio-quiet type 1 active galactic nuclei (AGN) in the wide-field ‘Cosmic Evolution Survey’ ...(COSMOS) have been studied for signs of evolution. For a sub-sample of 200 radio-quiet quasars with black hole mass estimates and host galaxy corrections, we studied their mean SEDs as a function of a broad range of redshift, bolometric luminosity, black hole mass and Eddington ratio, and compared them with the Elvis et al. (E94) type 1 AGN mean SED. We found that the mean SEDs in each bin are closely similar to each other, showing no statistical significant evidence of dependence on any of the analysed parameters. We also measured the SED dispersion as a function of these four parameters, and found no significant dependences. The dispersion of the XMM-COSMOS SEDs is generally larger than E94 SED dispersion in the ultraviolet, which might be due to the broader ‘window function’ for COSMOS quasars, and their X-ray-based selection.
The XXL Survey Farahi, Arya; Guglielmo, Valentina; Evrard, August E. ...
Astronomy & astrophysics,
12/2018, Volume:
620
Journal Article
Peer reviewed
Open access
Context. An X-ray survey with the XMM-Newton telescope, XMM-XXL, has identified hundreds of galaxy groups and clusters in two 25 deg2 fields. Combining spectroscopic and X-ray observations in one ...field, we determine how the kinetic energy of galaxies scales with hot gas temperature and also, by imposing prior constraints on the relative energies of galaxies and dark matter, infer a power-law scaling of total mass with temperature. Aims. Our goals are: i) to determine parameters of the scaling between galaxy velocity dispersion and X-ray temperature, T300 kpc, for the halos hosting XXL-selected clusters, and; ii) to infer the log-mean scaling of total halo mass with temperature, ⟨lnM200 | T300 kpc, z⟩. Methods. We applied an ensemble velocity likelihood to a sample of >1500 spectroscopic redshifts within 132 spectroscopically confirmed clusters with redshifts z < 0.6 to model, ⟨lnσgal | T300 kpc, z⟩, where σgal is the velocity dispersion of XXL cluster member galaxies and T300 kpc is a 300 kpc aperture temperature. To infer total halo mass we used a precise virial relation for massive halos calibrated by N-body simulations along with a single degree of freedom summarising galaxy velocity bias with respect to dark matter. Results. For the XXL-N cluster sample, we find σgal ∝ T300 kpc0.63±0.05 $\sigma_{\textrm{gal}} \propto {{T_{\textrm{300~kpc}}}^{0.63\pm0.05}$ σgal∝T300 kpc0.63±0.05, a slope significantly steeper than the self-similar expectation of 0.5. Assuming scale-independent galaxy velocity bias, we infer a mean logarithmic mass at a given X-ray temperature and redshift, 〈ln(E(z)M200/1014 M⊙)|T300 kpc, z〉 = πT + αT ln (T300 kpc/Tp) + βT ln (E(z)/E(zp)) $\langle \ln (E(z) M_{200}/10^{14} {{\, M_{\odot}}})|{{T_{\textrm{300~kpc}}},z\rangle=\pi_{T}+\alpha_{T}\ln\left({{T_{\textrm{300~kpc}}}/T_{\textrm{p}}\right)+\beta_{T}\ln\left(E(z)/E(z_{\textrm{p}})\right)$ 〈ln(E(z)M200/1014 M⊙)|T300 kpc,z〉=πT+αTln(T300 kpc/Tp)+βTln(E(z)/E(zp)) using pivot values kTp = 2.2 keV and zp = 0.25, with normalization πT = 0.45 ± 0.24 and slope αT = 1.89 ± 0.15. We obtain only weak constraints on redshift evolution, βT = −1.29 ± 1.14. Conclusions. The ratio of specific energies in hot gas and galaxies is scale dependent. Ensemble spectroscopic analysis is a viable method to infer mean scaling relations, particularly for the numerous low mass systems with small numbers of spectroscopic members per system. Galaxy velocity bias is the dominant systematic uncertainty in dynamical mass estimates.
We report a sizable class of type 1 active galactic nuclei (AGNs) with unusually weak near-infrared (1-3 Delta *mm) emission in the XMM-COSMOS type 1 AGN sample. The fraction of these 'hot-dust-poor' ...AGNs increases with redshift from 6% at low redshift (z < 2) to 20% at moderate high redshift (2 < z < 3.5). There is no clear trend of the fraction with other parameters: bolometric luminosity, Eddington ratio, black hole mass, and X-ray luminosity. The 3 Delta *mm emission relative to the 1 Delta *mm emission is a factor of 2-4 smaller than the typical Elvis et al. AGN spectral energy distribution (SED), which indicates a 'torus' covering factor of 2%-29%, a factor of 3-40 smaller than required by unified models. The weak hot dust emission seems to expose an extension of the accretion disk continuum in some of the source SEDs. We estimate the outer edge of their accretion disks to lie at (0.3-2.0) X 104 Schwarzschild radii, ~10-23 times the gravitational stability radii. Formation scenarios for these sources are discussed.
The active galaxy NGC 1275 lies at the center of the Perseus cluster of galaxies, being an archetypal BH-galaxy system that is supposed to fit well with the MBH-host scaling relations obtained for ...quiescent galaxies. Since it harbors an obscured AGN, only recently our group has been able to estimate its black hole mass. Here our aim is to pinpoint NGC 1275 on the less dispersed scaling relations, namely the MBH-σ⋆ and MBH−Lbul planes. Starting from our previous work (Ricci et al., 2017a), we estimate that NGC 1275 falls well outside the intrinsic dispersion of the MBH-σ⋆ plane being 1.2 dex (in black hole mass) displaced with respect to the scaling relations. We then perform a 2D morphological decomposition analysis on Spitzer/IRAC images at 3.6 μm and find that, beyond the bright compact nucleus that dominates the central emission, NGC 1275 follows a de Vaucouleurs profile with no sign of significant star formation nor clear merger remnants. Nonetheless, its displacement on the MBH−L3.6,bul plane with respect to the scaling relation is as high as observed in the MBH-σ⋆. We explore various scenarios to interpret such behaviors, of which the most realistic one is the evolutionary pattern followed by NGC 1275 to approach the scaling relation. We indeed speculate that NGC 1275 might be a specimen for those galaxies in which the black holes adjusted to its host.
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