We investigated the interstellar medium (ISM) properties of the disc and outflowing gas in the central regions of nine nearby Seyfert galaxies, all characterised by prominent conical or biconical ...outflows. These objects are part of the Measuring Active Galactic Nuclei Under MUSE Microscope (MAGNUM) survey, which aims to probe their physical conditions and ionisation mechanism by exploiting the unprecedented sensitivity of the Multi Unit Spectroscopic Explorer (MUSE), combined with its spatial and spectral coverage. Specifically, we studied the different properties of the gas in the disc and in the outflow with spatially and kinematically resolved maps by dividing the strongest emission lines in velocity bins. We associated the core of the lines with the disc, consistent with the stellar velocity, and the redshifted and the blueshifted wings with the outflow. We measured the reddening, density, ionisation parameter, and dominant ionisation source of the emitting gas for both components in each galaxy. We find that the outflowing gas is characterised by higher values of density and ionisation parameter than the disc, which presents a higher dust extinction. Moreover, we distinguish high- and low-ionisation regions across the portion of spatially resolved narrow-line region (NLR) traced by the outflowing gas. The high-ionisation regions characterised by the lowest N II/Hα and S II/Hα line ratios generally trace the innermost parts along the axis of the emitting cones where the S III/S II line ratio is enhanced, while the low-ionisation regions follow the cone edges and/or the regions perpendicular to the axis of the outflows, also characterised by a higher O III velocity dispersion. A possible scenario to explain these features relies on the presence of two distinct populations of line emitting clouds: one is optically thin to the radiation and is characterised by the highest excitation, while the other is optically thick and is impinged by a filtered, and thus harder, radiation field which generates strong low-excitation lines. The highest values of N II/Hα and S II/Hα line ratios may be due to shocks and/or a hard filtered radiation field from the active galactic nucleus.
High‐energy satellites, in particular XMM‐Newton, have clear synergies with ESO instruments. This is testified by the significant number of scientific publications based on data obtained with both ...facilities. In this article, we briefly review past synergies and discuss future possibilities.
We exploit the 7 Ms Chandra observations in the Chandra Deep Field-South (CDF-S), the deepest X-ray survey to date, coupled with CANDELS/GOODS-S data, to measure the total X-ray emission arising from ...2076 galaxies at 3.5 ≤ z < 6.5. This aim is achieved by stacking the Chandra data at the positions of optically selected galaxies, reaching effective exposure times of ≥109s. We detect significant (>3.7σ) X-ray emission from massive galaxies at z ≈ 4. We also report the detection of massive galaxies at z ≈ 5 at a 99.7 per cent confidence level (2.7σ), the highest significance ever obtained for X-ray emission from galaxies at such high redshifts. No significant signal is detected from galaxies at even higher redshifts. The stacking results place constraints on the BHAD associated with the known high-redshift galaxy samples, as well as on the SFRD at high redshift, assuming a range of prescriptions for X-ray emission due to X- ray binaries. We find that the X-ray emission from our sample is likely dominated by processes related to star formation. Our results show that low-rate mass accretion on to SMBHs in individually X-ray-undetected galaxies is negligible, compared with the BHAD measured for samples of X-ray detected AGN, for cosmic SMBH mass assembly at high redshift. We also place, for the first time, constraints on the faint-end of the AGN X-ray luminosity function (logLX ∼ 42) at z > 4, with evidence for fairly flat slopes. The implications of all of these findings are discussed in the context of the evolution of the AGN population at high redshift.
Quasar feedback in the form of powerful outflows is invoked as a key mechanism to quench star formation in galaxies, preventing massive galaxies to overgrow and producing the red colors of ...ellipticals. On the other hand, some models are also requiring "positive" active galactic nucleus feedback, inducing star formation in the host galaxy through enhanced gas pressure in the interstellar medium. However, finding observational evidence of the effects of both types of feedback is still one of the main challenges of extragalactic astronomy, as few observations of energetic and extended radiatively driven winds are available. Here we present SINFONI near infrared integral field spectroscopy of XID2028, an obscured, radio-quiet z = 1.59 QSO detected in the XMM-COSMOS survey, in which we clearly resolve a fast (1500 km s super(-1)) and extended (up to 13 kpc from the black hole) outflow in the OIII lines emitting gas, whose large velocity and outflow rate are not sustainable by star formation only. The narrow component of H alpha emission and the rest frame U-band flux from Hubble Space Telescope/Advanced Camera for Surveys imaging enable to map the current star formation in the host galaxy: both tracers independently show that the outflow position lies in the center of an empty cavity surrounded by star forming regions on its edge. The outflow is therefore removing the gas from the host galaxy ("negative feedback"), but also triggering star formation by outflow induced pressure at the edges ("positive feedback"). XID2028 represents the first example of a host galaxy showing both types of feedback simultaneously at work.
Abstract
The phase transition between galaxies and quasars is often identified with the rare population of hyper-luminous, hot dust-obscured galaxies. Galaxy formation models predict these systems to ...grow via mergers, that can deliver large amounts of gas toward their centers, induce intense bursts of star formation and feed their supermassive black holes. Here we report the detection of 24 galaxies emitting Lyman-
α
emission on projected physical scales of about 400 kpc around the hyper-luminous hot dust-obscured galaxy W0410-0913, at redshift
z
= 3.631, using Very Large Telescope observations. While this indicates that W0410-0913 evolves in a very dense environment, we do not find clear signs of mergers that could sustain its growth. Data suggest that if mergers occurred, as models expect, these would involve less massive satellites, with only a moderate impact on the internal interstellar medium of W0410-0913, which is sustained by a rotationally-supported fast-rotating molecular disk, as Atacama Large Millimeter Array observations suggest.
ABSTRACT
We present high-resolution (∼2.4 kpc) ALMA band 7 observations (rest-frame λ ∼ 250 $\mu$m) of three powerful z ∼ 2.5 quasars (Lbol = 1047.3–1047.5 erg s−1). These targets have previously ...been reported as showing evidence for suppressed star formation based on cavities in the narrow H α emission at the location of outflows traced with O iii emission. Here, we combine the ALMA observations with a re-analysis of the VLT/SINFONI data to map the rest-frame far-infrared emission, H α emission, and O iii emission. In all targets, we observe high velocity O iii gas (i.e. W80 ∼ 1000–2000 km s−1) across the whole galaxy. We do not identify any H α emission that is free from contamination from AGN-related processes; however, based on SED analyses, we show that the ALMA data contain a significant dust-obscured star formation component in two out of the three systems. This dust emission is found to be extended over ≈1.5–5.5 kpc in the nuclear regions, overlaps with the previously reported H α cavities and is co-spatial with the peak in surface brightness of the O iii outflows. In summary, within the resolution and sensitivity limits of the data, we do not see any evidence for a instantaneous shut down of in situ star formation caused directly by the outflows. However, similar to the conclusions of previous studies and based on our measured star formation rates, we do not rule out that the global host galaxy star formation could be suppressed on longer time-scales by the cumulative effect of quasar episodes during the growth of these massive black holes.
ABSTRACT
We present the first results from the Quasar Feedback Survey, a sample of 42 z < 0.2, O iii luminous AGNs ( LO III > 1042.1 ergs s−1) with moderate radio luminosities (i.e. L1.4GHz > ...1023.4 W Hz−1; median L1.4GHz = 5.9 × 1023 W Hz−1). Using high spatial resolution (∼0.3–1 arcsec), 1.5–6 GHz radio images from the Very Large Array, we find that 67 per cent of the sample have spatially extended radio features on ∼1–60 kpc scales. The radio sizes and morphologies suggest that these may be lower radio luminosity versions of compact, radio-loud AGNs. By combining the radio-to-infrared excess parameter, spectral index, radio morphology, and brightness temperature, we find radio emission in at least 57 per cent of the sample that is associated with AGN-related processes (e.g. jets, quasar-driven winds, or coronal emission). This is despite only 9.5–21 per cent being classified as radio-loud using traditional criteria. The origin of the radio emission in the remainder of the sample is unclear. We find that both the established anticorrelation between radio size and the width of the O iii line, and the known trend for the most O iii luminous AGNs to be associated with spatially extended radio emission, also hold for our sample of moderate radio luminosity quasars. These observations add to the growing evidence of a connection between the radio emission and ionized gas in quasar host galaxies. This work lays the foundation for deeper investigations into the drivers and impact of feedback in this unique sample.
We present an investigation into how well the properties of the accretion flow on to a supermassive black hole may be coupled to those of the overlying hot corona. To do so, we specifically measure ...the characteristic spectral index, Γ, of a power-law energy distribution, over an energy range of 2-10 keV, for X-ray selected, broad-lined radio-quiet active galactic nuclei (AGN) up to z ∼ 2 in Cosmic Evolution Survey (COSMOS) and Extended Chandra Deep Field South (E-CDF-S). We test the previously reported dependence between Γ and black hole mass, full width at half-maximum (FWHM) and Eddington ratio using a sample of AGN covering a broad range in these parameters based on both the Mg ii and Hα emission lines with the later afforded by recent near-infrared spectroscopic observations using Subaru/Fibre Multi Object Spectrograph. We calculate the Eddington ratios, λEdd, for sources where a bolometric luminosity (L
Bol) has been presented in the literature, based on spectral energy distribution fitting, or, for sources where these data do not exist, we calculate L
Bol using a bolometric correction to the X-ray luminosity, derived from a relationship between the bolometric correction and L
X/L
3000. From a sample of 69 X-ray bright sources (>250 counts), where Γ can be measured with greatest precision, with an estimate of L
Bol, we find a statistically significant correlation between Γ and λEdd, which is highly significant with a chance probability of 6.59× 10−8. A statistically significant correlation between Γ and the FWHM of the optical lines is confirmed, but at lower significance than with λEdd indicating that λEdd is the key parameter driving conditions in the corona. Linear regression analysis reveals that Γ = (0.32 ± 0.05) log10λEdd + (2.27 ± 0.06) and Γ = (−0.69 ± 0.11) log10(FWHM/km s−1) + (4.44 ± 0.42). Our results on Γ-λEdd are in very good agreement with previous results. While the Γ-λEdd relationship means that X-ray spectroscopy may be used to estimate black hole accretion rate, considerable dispersion in the correlation does not make this viable for single sources, however could be valuable for large X-ray spectral samples, such as those to be produced by eROSITA.
Abstract
We present the “SINS/zC-SINF AO survey” of 35 star-forming galaxies, the largest sample with deep adaptive optics (AO)–assisted near-infrared integral field spectroscopy at
z
∼ 2. The ...observations, taken with SINFONI at the Very Large Telescope, resolve the H
α
and N
ii
emission and kinematics on scales of ∼1.5 kpc. The sample probes the massive (
M
⋆
∼ 2 × 10
9
− 3 × 10
11
M
⊙
), actively star-forming (SFR ∼ 10–600
M
⊙
yr
−1
) part of the
z
∼ 2 galaxy population over a wide range of colors ((
U
−
V
)
rest
∼ 0.15–1.5 mag) and half-light radii (
R
e,H
∼ 1–8.5 kpc). The sample overlaps largely with the “main sequence” of star-forming galaxies in the same redshift range to a similar
K
AB
= 23 mag limit; it has ∼0.3 dex higher median specific SFR, ∼0.1 mag bluer median (
U
−
V
)
rest
color, and ∼10% larger median rest-optical size. We describe the observations, data reduction, and extraction of basic flux and kinematic properties. With typically 3–4 times higher resolution and 4–5 times longer integrations (up to 23 hr) than the seeing-limited data sets of the same objects, the AO data reveal much more detail in morphology and kinematics. The complete AO observations confirm the majority of kinematically classified disks and the typically elevated disk velocity dispersions previously reported based on subsets of the data. We derive typically flat or slightly negative radial N
ii
/
gradients, with no significant trend with global galaxy properties, kinematic nature, or the presence of an AGN. Azimuthal variations in N
ii
/
are seen in several sources and are associated with ionized gas outflows and possibly more metal-poor star-forming clumps or small companions. The reduced AO data are made publicly available (
http://www.mpe.mpg.de/ir/SINS/SINS-zcSINF-data
).
We present the evolutionary properties and luminosity functions of the radio sources belonging to the Chandra Deep Field South Very Large Array survey, which reaches a flux density limit at 1.4 GHz ...of 43 Delta *mJy at the field center and redshift ~5 and which includes the first radio-selected complete sample of radio-quiet active galactic nuclei (AGNs). We use a new, comprehensive classification scheme based on radio, far- and near-IR, optical, and X-ray data to disentangle star-forming galaxies (SFGs) from AGNs and radio-quiet from radio-loud AGNs. We confirm our previous result that SFGs become dominant only below 0.1 mJy. The sub-millijansky radio sky turns out to be a complex mix of SFGs and radio-quiet AGNs evolving at a similar, strong rate; non-evolving low-luminosity radio galaxies; and declining radio powerful (P 3 X 1024 W Hz--1) AGNs. Our results suggest that radio emission from radio-quiet AGNs is closely related to star formation. The detection of compact, high brightness temperature cores in several nearby radio-quiet AGNs can be explained by the coexistence of two components, one non-evolving and AGN related and one evolving and star formation related. Radio-quiet AGNs are an important class of sub-millijansky sources, accounting for ~30% of the sample and ~60% of all AGNs, and outnumbering radio-loud AGNs at 0.1 mJy. This implies that future, large area sub-millijansky surveys, given the appropriate ancillary multiwavelength data, have the potential of being able to assemble vast samples of radio-quiet AGNs, bypassing the problems of obscuration that plague the optical and soft X-ray bands.
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