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Published March 20, 2016 | Version Published + Submitted
Journal Article Open

Peering through the Dust: NuSTAR Observations of Two FIRST-2MASS Red Quasars

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Abstract

Some reddened quasars appear to be transitional objects in the merger-induced black hole growth/galaxy evolution paradigm, where a heavily obscured nucleus starts to be unveiled by powerful quasar winds evacuating the surrounding cocoon of dust and gas. Hard X-ray observations are able to peer through this gas and dust, revealing the properties of circumnuclear obscuration. Here, we present NuSTAR and XMM-Newton/Chandra observations of FIRST-2MASS selected red quasars F2M 0830+3759 and F2M 1227+3214. We find that though F2M 0830+3759 is moderately obscured (N_(H,Z) = 2.1 ± 0.2 × 10^(22) cm^(−2)) and F2M 1227+3214 is mildly absorbed (N_(H,Z) = 3.4^(+0.8)_(−0.7) × 10^(21) cm^(−2)) along the line-of-sight, heavier global obscuration may be present in both sources, with N_(H,S) = 3.7^(+4.1)_(−2.6) × 10^(23) cm^(−2) and < 5.5 × 10^(23) cm^(−2), for F2M 0830+3759 and F2M 1227+3214, respectively. F2M 0830+3759 also has an excess of soft X-ray emission below 1 keV which is well accommodated by a model where 7% of the intrinsic AGN X-ray emission is scattered into the line-of-sight. While F2M 1227+3214 has a dust-to-gas ratio (E(B − V )/N_H) consistent with the Galactic value, the E(B−V )/NH value for F2M 0830+3759 is lower than the Galactic standard, consistent with the paradigm that the dust resides on galactic scales while the X-ray reprocessing gas originates within the dust-sublimation zone of the broad-line-region. The X-ray and 6.1μm luminosities of these red quasars are consistent with the empirical relations derived for high-luminosity, unobscured quasars, extending the parameter space of obscured AGN previously observed by NuSTAR to higher luminosities.

Additional Information

© 2016 The American Astronomical Society. Received 2015 November 30; accepted 2016 February 9; published 2016 March 21. We thank the referee for a careful reading of this manuscript and helpful comments. This work was supported under NASA contract No. NNG08FD60C, and made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. We thank the NuSTAR Operations, Software and Calibration teams for support with the execution and analysis of these observations. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA). AR is supported by the Gruber Science Fellowship. EG acknowledges the generous support of the Cottrell College Award through the Research Corporation for Science Advancement. WNB acknowledges support from Caltech NuSTAR subcontract 44A-1092750 and NASA ADP grant NNX10AC99G. RCH acknowledges support from NASA through ADAP award NNX12AE38G, the National Science Foundation through grant nos. 1211096 and 1515364, a Sloan Research Fellowship, and a Dartmouth Class of 1962 Faculty Fellowship. CR acknowledges financial support from the CONICYT-Chile grants "EMBIGGEN" Anillo ACT1101, FONDECYT 1141218, Basal-CATA PFB-06/2007. Facilities: NuSTAR,XMM

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Published - apj_820_1_70.pdf

Submitted - 1602.03532v1.pdf

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Additional details

Identifiers

Eprint ID
65470
Resolver ID
CaltechAUTHORS:20160318-080750044

Related works

Describes
http://arxiv.org/abs/1602.03532 (URL)

Funding

NASA
NNG08FD60C
NASA/JPL/Caltech
Gruber Science Fellowship
Cottrell Scholar of Research Corporation
NuSTAR
44A-1092750
NASA
NNX10AC99G
NASA
NNX12AE38G
NSF
1211096
NSF
1515364
Alfred P. Sloan Foundation
Dartmouth Class of 1962 Faculty Fellowship
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)
Anillo ACT1101
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
1141218
Basal-CATA
PFB-06/2007

Dates

Created
2016-03-18
Created from EPrint's datestamp field
Updated
2021-11-10
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
NuSTAR, Space Radiation Laboratory
Other Numbering System Name
Space Radiation Laboratory
Other Numbering System Identifier
2016-61