X‐Raying the Ultraluminous Infrared Starburst Galaxy and Broad Absorption Line QSO Markarian 231 with<i>Chandra</i>

Gallagher, S. C.; Brandt, W. N.; Chartas, G.; Garmire, G. P.; Sambruna, R. M.

doi:10.1086/339171

Cited by 77 publications

(108 citation statements)

References 74 publications

(133 reference statements)

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“…The inferred densities [n(H 2 ) $ 10 4 cm À3 ] may explain the submillimeter CO emission detected by PIW07 and somewhat lower densities (a few ; 10 3 cm À3 ) can account for the [O i] line emission. We do not however rule out the possibility that some of the FIR emission arises from a more extended region, such as the outermost disk observed by DS98 in the millimeter CO lines or the much more extended region observed in soft X-rays (Gallagher et al 2002).…”

Section: Discussionmentioning

confidence: 79%

High‐excitation OH and H₂O Lines in Markarian 231: The Molecular Signatures of Compact Far‐infrared Continuum Sources

González-Alfonso

Smith

Ashby

et al. 2008

ApJ

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The ISO LWS far-infrared spectrum of the ultraluminous galaxy Mrk 231 shows OH and H 2 O lines in absorption from energy levels up to 300 K above the ground state, and emission in the [O i] 63 m and [C ii] 158 m lines. Our analysis shows that OH and H 2 O are radiatively pumped by the far-infrared continuum emission of the galaxy. The absorptions in the high-excitation lines require high far-infrared radiation densities, allowing us to constrain the properties of the underlying continuum source. The bulk of the far-infrared continuum arises from a warm (T dust ¼ 70 100 K), optically thick ( 100 m ¼ 1 2) medium of effective diameter 200-400 pc. In our best-fit model of total luminosity L IR , the observed OH and H 2 O high-lying lines arise from a luminous (L/L IR $ 0:56) region with radius $100 pc. The high surface brightness of this component suggests that its infrared emission is dominated by the AGN. The derived column densities N (OH) k 10 17 cm À2 and N (H 2 O) k 6 ; 10 16 cm À2 may indicate X-ray dominated region (XDR) chemistry, although significant starburst chemistry cannot be ruled out. The lower-lying OH, [C ii] 158 m, and [O i] 63 m lines arise from a more extended ($350 pc) starburst region. We show that the [C ii] deficit in Mrk 231 is compatible with a high average abundance of C + because of an extreme overall luminosity to gas mass ratio. Therefore, a [C ii] deficit may indicate a significant contribution to the luminosity by an AGN, and/or by extremely efficient star formation.

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Section: Discussionmentioning

confidence: 79%

High‐excitation OH and H₂O Lines in Markarian 231: The Molecular Signatures of Compact Far‐infrared Continuum Sources

González-Alfonso

Smith

Ashby

et al. 2008

ApJ

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“…This weak-line source may be a highredshift analogue of Mrk 231, a Compton thick AGN with a weak Fe K line in the local Universe (e.g., Braito et al 2004;Gallagher et al 2002;Iwasawa et al 2011, and other references therein). The large EW observed in PID 114 (Table 5) agrees with an Fe K line expected from a reflection-dominated spectrum from cold medium, giving a support to the possibility of a Compton thick source.…”

Section: -20 Kev Excess Sourcesmentioning

confidence: 95%

The XMM deep survey in the CDF-S

Iwasawa

Gilli

Vignali

et al. 2012

A&A

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We present results on a search of heavily obscured active galaxies z > 1.7 using the rest-frame 9−20 keV excess for X-ray sources detected in the deep XMM-CDFS survey. Out of 176 sources selected with the conservative detection criteria (>8σ) in the first source catalogue of Ranalli et al. (in prep.), 46 objects lie in the redshift range of interest with the median redshiftz 2.5. Their typical rest-frame 10−20 keV luminosity is 10 44 erg s −1 , as observed. Among optically faint objects that lack spectroscopic redshift, four were found to be strongly absorbed X-ray sources, and the enhanced Fe K emission or absorption features in their X-ray spectra were used to obtain X-ray spectroscopic redshifts. Using the X-ray colour-colour diagram based on the rest-frame 3−5 keV, 5−9 keV, and 9−20 keV bands, seven objects were selected for their 9−20 keV excess and were found to be strongly absorbed X-ray sources with column density of N H ≥ 0.6 × 10 24 cm −2 , including two possible Compton thick sources. While they are emitting at quasar luminosity, ∼3/4 of the sample objects are found to be absorbed by N H > 10 22 cm −2 . A comparison with local AGN at the matched luminosity suggests an increasing trend of the absorbed source fraction for high-luminosity AGN towards high redshifts.

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“…X-ray observations by ROSAT, ASCA (Turner 1999;Iwasawa 1999;Maloney & Reynolds 2000), and more recently Chandra (Gallagher et al 2002;Ptak et al 2003) have revealed the presence of extended soft X-ray emission with a thermal origin that is likely to be associated with the circumnuclear starburst and a hard and flat (Γ 0.7) powerlaw component, as well as an Fe K α emission line with EW ∼ 300 eV (the line was detected by ASCA but not by Chandra). From combined XMMNewton and BeppoSAX observations of MRK 231, Braito et al (2004) −0.25 ), a soft component fitted with two thermal plasma models with temperatures kT 0.33 keV and 0.99 keV, and narrow emission lines at 6.28 keV and 6.66 keV.…”

Section: Mrk 231mentioning

confidence: 99%

X-ray spectral properties of Seyfert galaxies and the unification scheme

Singh

Shastri

Risaliti

2011

A&A

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Context. The unification scheme of Seyfert galaxies predicts that the observed differences between types 1 and 2 Seyfert galaxies are solely due to the differing orientations of the toroidal-shaped obscuring material around AGN. The observed X-ray spectra of Seyfert type 2s compared to type 1s are expected to be affected by higher absorbing column density owing to the edge-on view of the obscuring torus. Aims. We study the 0.5-10 keV X-ray spectral properties of Seyfert type 1s and type 2s with the aim of testing the predictions of Seyfert unification scheme in the X-ray regime. Methods. We use an optically selected Seyfert sample in which type 1s and type 2s have matched distributions in parameters that are independent of the orientation of AGN and the host galaxy. Results. The 0.5-10 keV XMM-Newton pn X-ray spectra of Seyfert galaxies are in general best fitted with a model that consists of (i) an absorbed powerlaw; (ii) a narrow Gaussian fitted to the Fe Kα emission line; and (iii) an often seen soft-excess component characterized by either a thermal plasma model with temperature kT ∼ 0.1-1.0 keV or a steep powerlaw or both. The 2.0-10 keV hard X-ray continuum emission in several Seyfert type 2s is dominated by reflection and suggests the Compton-thick obscuration. Results of the statistical comparison between the distributions of (i) the observed X-ray luminosities in the soft (0.5-2.0 keV) and hard (2.0-10.0 keV) bands; (ii) the X-ray absorbing column densities; (iii) the equivalent widths of Fe Kα line; and (iv) the flux ratios of hard X-ray to [OIII] λ5007 Å, for the two Seyfert subtypes are consistent with the obscuration and orientation-based unification scheme.

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X‐Raying the Ultraluminous Infrared Starburst Galaxy and Broad Absorption Line QSO Markarian 231 withChandra

Cited by 77 publications

References 74 publications

High‐excitation OH and H₂O Lines in Markarian 231: The Molecular Signatures of Compact Far‐infrared Continuum Sources

High‐excitation OH and H₂O Lines in Markarian 231: The Molecular Signatures of Compact Far‐infrared Continuum Sources

The XMM deep survey in the CDF-S

X-ray spectral properties of Seyfert galaxies and the unification scheme

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X‐Raying the Ultraluminous Infrared Starburst Galaxy and Broad Absorption Line QSO Markarian 231 withChandra

Cited by 77 publications

References 74 publications

High‐excitation OH and H2O Lines in Markarian 231: The Molecular Signatures of Compact Far‐infrared Continuum Sources

High‐excitation OH and H2O Lines in Markarian 231: The Molecular Signatures of Compact Far‐infrared Continuum Sources

The XMM deep survey in the CDF-S

X-ray spectral properties of Seyfert galaxies and the unification scheme

Contact Info

Product

Resources

About

High‐excitation OH and H₂O Lines in Markarian 231: The Molecular Signatures of Compact Far‐infrared Continuum Sources

High‐excitation OH and H₂O Lines in Markarian 231: The Molecular Signatures of Compact Far‐infrared Continuum Sources