The Chandra Deep Field North Survey. XIV. X-Ray–Detected Obscured AGN[CLC]s[/CLC] and Starburst Galaxies in the Bright Submillimeter Source Population

Alexander, D. M.; Bauer, F. E.; Brandt, W. N.; Hornschemeier, A. E.; Vignali, C.; Garmire, G. P.; Schneider, Donald P.; Chartas, G.; Gallagher, S. C.

doi:10.1086/346088

Cited by 165 publications

(32 citation statements)

References 113 publications

(162 reference statements)

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“…The rest-frame 1.4 GHz luminosities were calculated for S82 by assuming a uniform spectral slope of α = −0.7, following Alexander et al (2003) 3 . For the C3GHz sample, the 1.4 GHz fluxes were taken from the VLA-COSMOS 1.4 GHz survey (Schinnerer et al 2007) when available, and calculated from the 3 GHz fluxes assuming a uniform spectral slope of α = −0.7 otherwise.…”

Section: Final Radio-detected Samples: S82 and C3ghzmentioning

confidence: 99%

Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars

Fawcett

Alexander

Rosario

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We have recently used the Faint Images of the Radio Sky at Twenty-centimeters (FIRST) survey to show that red quasars have fundamentally different radio properties to typical blue quasars: a significant (factor ≈ 3) enhancement in the radio-detection fraction, which arises from systems around the radio-quiet threshold with compact (< 5 ) radio morphologies. To gain greater insight into these physical differences, here we use the DR14 Sloan Digital Sky Survey (SDSS) and more sensitive, higher resolution radio data from the Very Large Array (VLA) Stripe 82 (S82) and VLA-COSMOS 3 GHz (C3GHz) surveys. With the S82 data, we perform morphological analyses at a resolution and depth three times that of the FIRST radio survey, and confirm an enhancement in radio-faint and compact red quasars over typical quasars; we now also find tentative evidence for an enhancement in red quasars with slightly extended radio structures (16-43 kpc at z = 1.5). These analyses are complemented by C3GHz, which is deep enough to detect radio emission from star-formation processes. From our data we find that the radio enhancement from red quasars is due to AGN activity on compact scales ( 43 kpc) for radio-intermediate-radio-quiet sources (−5 < R < −3.4, where R = L 1.4GHz /L 6µm ), which decreases at R < −5 as the radio emission from star-formation starts to dilute the AGN component. Overall our results argue against a simple orientation scenario and are consistent with red quasars representing a younger, earlier phase in the overall evolution of quasars.

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Section: Final Radio-detected Samples: S82 and C3ghzmentioning

confidence: 99%

Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars

Fawcett

Alexander

Rosario

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…SMGs harbouring hidden AGNs is not a new concept, and in some sources, Xray observations have already revealed obscured AGNs (e.g. Alexander et al 2003;Borys et al 2005). Although both Chandra and XMM-Newton have observed the field, the observations targeted the foreground X-ray bright galaxy cluster making it difficult to resolve and disentangle emission from the QSO and companion.…”

Section: Quasar-star-forming Companion Systemsmentioning

confidence: 99%

SMM J04135+10277: a distant QSO–starburst system caught by ALMA

Fogasy

Knudsen

Drouart

et al. 2020

Monthly Notices of the Royal Astronomical Society

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The gas content of galaxies is a key factor for their growth, starting from star formation and black hole accretion to galaxy mergers. Thus, characterising its properties through observations of tracers like the CO emission line is of big importance in order to understand the bigger picture of galaxy evolution. We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of dust continuum, CO(5-4) and CO(8-7) line emission in the quasar-star-forming companion system SMM J04135+10277 (z = 2.84). Earlier low-J CO studies of this system found a huge molecular gas reservoir associated to the companion galaxy, while the quasar appeared gas-poor. Our CO observations revealed that the host galaxy of the quasar is also gas-rich, with an estimated molecular gas mass of ∼ (0.7−2.3)×10 10 M . The CO line profiles of the companion galaxy are very broad (∼ 1000 km s −1 ), and show signs of rotation of a compact, massive system. In contrast to previous far-infrared observations, we resolve the continuum emission and detect both sources, with the companion galaxy dominating the dust continuum and the quasar having a ∼ 25% contribution to the total dust emission. By fitting the infrared spectral energy distribution of the sources with MR-MOOSE and empirical templates, the infrared luminosities of the quasar and the companion are in the range of L IR,QSO ∼ (2.1 − 9.6) × 10 12 L and L IR,Comp. ∼ (2.4 − 24) × 10 12 L , while the estimated star formation rates are ∼ 210 − 960 M yr −1 and ∼ 240 − 2400 M yr −1 , respectively. Our results demonstrate that non-detection of low-J CO transition lines in similar sources does not necessarily imply the absence of massive molecular gas reservoir but that the excitation conditions favour the excitation of high-J transitions.

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“…Ultra-deep Chandra observations (the 2 Ms Chandra DeepField-North survey; Alexander et al 2003a) have shown that at least ≈28-50% of the bright SMG population host heavily obscured AGNs (e.g., Alexander et al 2003bAlexander et al , 2005aAlexander et al , 2005c, implying joint growth of the galaxy and black hole (see also Ivison et al 2002;Wang et al 2004;Pope et al 2006). 9 The energetics of the AGNs measured at X-ray and mid-infrared (mid-IR) wavelengths are (typically) too low to explain the huge bolometric output of these objects (L bol ≈ 10 12 -10 13 L ; e.g., Ivison et al 2004;Alexander et al 2003bAlexander et al , 2005aLutz et al 2005), which appears to be dominated by star-formation processes (as shown by the strong star-formation signatures in the mid-IR spectra; e.g., Menéndez-Delmestre et al 2007;Valiante et al 2007;Pope et al 2008).…”

Section: Introductionmentioning

confidence: 99%

“…9 The energetics of the AGNs measured at X-ray and mid-infrared (mid-IR) wavelengths are (typically) too low to explain the huge bolometric output of these objects (L bol ≈ 10 12 -10 13 L ; e.g., Ivison et al 2004;Alexander et al 2003bAlexander et al , 2005aLutz et al 2005), which appears to be dominated by star-formation processes (as shown by the strong star-formation signatures in the mid-IR spectra; e.g., Menéndez-Delmestre et al 2007;Valiante et al 2007;Pope et al 2008). 10 However, the large AGN fraction implies that the black holes are growing almost continuously throughout periods of vigorous star formation.…”

Section: Introductionmentioning

confidence: 99%

WEIGHING THE BLACK HOLES INz≈ 2 SUBMILLIMETER-EMITTING GALAXIES HOSTING ACTIVE GALACTIC NUCLEI

Alexander

Brandt

Smail

et al. 2008

The Astronomical Journal

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We place direct observational constraints on the black-hole masses (M BH ) of the cosmologically important z ≈ 2 submillimeter-emitting galaxy (SMG; f 850 µm 4 mJy) population, and use measured host-galaxy masses to explore their evolutionary status. We employ the well-established virial black-hole mass estimator to "weigh" the black holes of a sample of z ≈ 2 SMGs which exhibit broad Hα or Hβ emission. We find that the average black-hole mass and Eddington ratio (η = L bol /L Edd ) of the lower-luminosity broad-line SMGs (L X ≈ 10 44 erg s −1 ) are log(M BH /M ) ≈ 8.0 and η ≈ 0.2, respectively; by comparison, X-ray-luminous broad-line SMGs (L X ≈ 10 45 erg s −1 ) have log(M BH /M ) ≈ 8.4 and η ≈ 0.6. The lower-luminosity broad-line SMGs lie in the same location of the L X -L FIR plane as more typical SMGs hosting X-ray-obscured active galactic nuclei and may be intrinsically similar systems, but orientated so that the rest-frame optical nucleus is visible. Under this hypothesis, we conclude that SMGs host black holes with log(M BH /M ) ≈ 7.8; we find supporting evidence from observations of local ultra-luminous infrared galaxies. Combining these black-hole mass constraints with measured host-galaxy masses, we find that the black holes in SMGs are 3 times smaller than those found in comparably massive normal galaxies in the local universe, albeit with considerable uncertainty, and 10 times smaller than those predicted for z ≈ 2 luminous quasars and radio galaxies. These results imply that the growth of the black hole lags that of the host galaxy in SMGs, in stark contrast with that previously suggested for radio galaxies and luminous quasars at z ≈ 2. On the basis of current host-galaxy mass constraints, we show that SMGs and their descendants cannot lie significantly above the locally defined M BH -M GAL relationship. We argue that the black holes in the z ≈ 0 descendents of SMGs will have log(M BH /M ) ≈ 8.6, indicating that they only need to grow by a factor of ≈6 by the present day. We show that this amount of black-hole growth can be achieved within current estimates for the submillimeter-bright lifetime of SMGs, provided that the black holes can grow at rates close to the Eddington limit.

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The Chandra Deep Field North Survey. XIV. X-Ray–Detected Obscured AGN[CLC]s[/CLC] and Starburst Galaxies in the Bright Submillimeter Source Population

Cited by 165 publications

References 113 publications

Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars

Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars

SMM J04135+10277: a distant QSO–starburst system caught by ALMA

WEIGHING THE BLACK HOLES INz≈ 2 SUBMILLIMETER-EMITTING GALAXIES HOSTING ACTIVE GALACTIC NUCLEI

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