NuSTAR and Keck Observations of Heavily Obscured Quasars Selected by WISE

Yan, Wei; Hickox, Ryan C.; Hainline, Kevin; Stern, Daniel; Lansbury, G. B.; Alexander, D. M.; Hviding, Raphael E.; Assef, Roberto J.; Ballantyne, D. R.; DiPompeo, Michael A.; Lanz, Lauranne; Carroll, Christopher M.; Koss, Michael; Lamperti, Isabella; Civano, F.; Moro, A. Del; Gandhi, P.; Myers, Adam D.

doi:10.3847/1538-4357/aaeed4

Cited by 27 publications

(30 citation statements)

References 112 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This value is comparable to that found in W0204-0506, while those found in W0116-0505 and W0220+0137 are lower. Unfortunately the large uncertainties in this quantity make this result difficult to interpret, but it is worth noting that recently Yan et al (2019) identified a very low dust-to-gas ratio of ≈4×10 −25 cm 2 for a heavily obscured nearby quasar at z=0.218 with N H ≈3× 10 25 cm −2 , with around N H ≈10 23 cm −2 coming from the ISM, which could be a better analog to our objects. If the dustto-gas ratio is indeed significantly lower in W0116-0505 and W0220+0137 than in W0204-0506, it could either imply a low metallicity for the former systems such that there is a deficit of dust overall in the host galaxy, or that a higher than typical fraction of absorbing gas exists within the dust sublimation radius of the accretion disk.…”

Section: X-ray Data Modelingmentioning

confidence: 73%

Hot Dust-obscured Galaxies with Excess Blue Light

Assef

Brightman

Walton

et al. 2020

ApJ

Self Cite

View full text Add to dashboard Cite

Hot dust-obscured galaxies (Hot DOGs) are among the most luminous galaxies in the universe. Powered by highly obscured, possibly Compton-thick, active galactic nuclei (AGNs), Hot DOGs are characterized by spectral energy distributions that are very red in the mid-infrared yet dominated by the host galaxy stellar emission in the UV and optical. An earlier study identified a subsample of Hot DOGs with significantly enhanced UV emission. One target, W0204-0506, was studied in detail and, based on Chandra observations, it was concluded that the enhanced emission was most likely due to either extreme unobscured star formation (star formation rate>1000 M e yr −1) or to light from the highly obscured AGN scattered by gas or dust into our line of sight. Here, we present a follow-up study of W0204-0506 as well as two more Hot DOGs with excess UV emission. For the two new objects we obtained Chandra/ACIS-S observations, and for all three targets we obtained Hubble Space Telescope/WFC3 F555W and F160W imaging. The analysis of these observations, combined with multiwavelength photometry and UV/optical spectroscopy suggests that UV emission is most likely dominated by light from the central highly obscured, hyperluminous AGN that has been scattered into our line of sight, by either gas or dust. We cannot decisively rule out, however, that star formation or a second AGN in the system may significantly contribute to the UV excess of these targets.

show abstract

Section: X-ray Data Modelingmentioning

confidence: 73%

Hot Dust-obscured Galaxies with Excess Blue Light

Assef

Brightman

Walton

et al. 2020

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…Our models need to be able to recover the following observational constraints: (1) the host M halo for our simulated obscured and unobscured quasars, as well as (2) Yan et al 2019). We note that we adopt such a broad observed obscured fraction to reflect the uncertainty due to the difficulty of detecting heavily-obscured AGN.…”

Section: Resultsmentioning

confidence: 99%

“…Using relationships between host galaxy gas content and stellar mass as presented in and Pannella et al (2009), it was also possible to model quasar obscuration as a function of its host galaxy's stellar mass. We find that although some of these models were able to produce host M halo that fell within the range of clustering measurements, they are not viable since the obscured fractions for these populations were outside the observed range (e.g., Treister et al 2008;Polletta et al 2008;DiPompeo et al 2016b;Yan et al 2019). We also considered the effect of allowing our simulated quasars to be obscured by the parsec-scale dusty torus and by its host galaxy's interstellar gas.…”

Section: Discussionmentioning

confidence: 99%

Physical Models for the Clustering of Obscured and Unobscured Quasars

Whalen

Hickox

DiPompeo

et al. 2020

ApJ

Self Cite

View full text Add to dashboard Cite

Clustering measurements of obscured and unobscured quasars show that obscured quasars reside in more massive dark matter halos than their unobscured counterparts. These results are inconsistent with simple unified (torus) scenarios, but might be explained by models in which the distribution of obscuring material depends on Eddington ratio or galaxy stellar mass. We test these possibilities by constructing simple physical models to compare to observed AGN populations. We find that previously observed relationships between obscuration and Eddington ratio or stellar mass are not sufficient reproduce the observed quasar clustering results ( log M halo /M = 12.94 +0.10 −0.11 and log M halo /M = 12.49 +0.08 −0.08 for obscured and unobscured populations, respectively) while maintaining the observed fraction of obscured quasars (30-65%). This work suggests that evolutionary models, in which obscuration evolves on the typical timescale for black hole growth, are necessary to understand the observed clustering of mid-IR selected quasars.

show abstract

“…In this case, the expected upper-bound reaches to log(L 2−10 /erg s −1 ) = 42.92, or log(L bol /erg s −1 ) = 44.22, exceeding the upper-bound obtained from the Spitzer /IRS spectra. However, this situation is unlikely because the reprocessed infrared emission should be observed even in such highly obscured situation, contributing to the Spitzer /IRS spectra (e.g., Yan et al 2019). Thus, we conclude that the central engine of Arp 187 is likely to be dead, even if we consider the Compton-thick level obscuration, but the extreme absorption reaching N H = 10 25 cm −2 is also unlikely.…”

Section: Very Faint Agn Even If It Is Highly Obscuredmentioning

confidence: 99%

NuSTAR Discovery of Dead Quasar Engine in Arp 187

Ichikawa

Kawamuro

Shidatsu

et al. 2019

ApJL

View full text Add to dashboard Cite

Recent active galactic nucleus (AGN) and quasar surveys have revealed a population showing rapid AGN luminosity variability by a factor of ∼ 10. Here we present the most drastic AGN luminosity decline by a factor of 10 3 constrained by a NuSTAR X-ray observation of the nearby galaxy Arp 187, which is a promising "dead" quasar whose current activity seems quiet but whose past activity of L bol ∼ 10 46 erg s −1 is still observable at a large scale by its light echo. The obtained upper bound of the X-ray luminosity is log(L 2−10 keV /erg s −1 ) < 41.2, corresponding to log(L bol /erg s −1 ) < 42.5, indicating an inactive central engine. Even if a putative torus model with N H ∼ 1.5 × 10 24 cm −2 is assumed, the strong upper-bound still holds with log(L 2−10 keV /erg s −1 ) < 41.8 or log(L bol /erg s −1 ) < 43.1. Given the expected size of the narrow line region, this luminosity decrease by a factor of 10 3 must have occurred within 10 4 yr. This extremely rapid luminosity/accretion shutdown is puzzling and it requires one burst-like accretion mechanism producing a clear outer boundary for an accretion disk. We raise two possible scenarios realizing such an accretion mechanism: a mass accretion 1) by the tidal disruption of a molecular cloud and/or 2) by the gas depletion as a result of vigorous nuclear starformation after rapid mass inflow to the central engine.

show abstract

NuSTAR and Keck Observations of Heavily Obscured Quasars Selected by WISE

Cited by 27 publications

References 112 publications

Hot Dust-obscured Galaxies with Excess Blue Light

Hot Dust-obscured Galaxies with Excess Blue Light

Physical Models for the Clustering of Obscured and Unobscured Quasars

NuSTAR Discovery of Dead Quasar Engine in Arp 187

Contact Info

Product

Resources

About