The Ultra-fast Outflow of the Quasar PG1211+143 as Viewed by Time-averaged Chandra Grating Spectroscopy

Danehkar, Ashkbiz and Nowak, Michael A and Lee, Julia C and Kriss, Gerard A and Young, Andrew J and Hardcastle, Martin J and Chakravorty, Susmita and Fang, Taotao and Neilsen, Joseph and Rahoui, Farid and Smith, Randall K (2018) The Ultra-fast Outflow of the Quasar PG1211+143 as Viewed by Time-averaged Chandra Grating Spectroscopy. In: ASTROPHYSICAL JOURNAL, 853 (2).

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Abstract

We present a detailed X-ray spectral study of the quasar PG 1211+143 based on Chandra High Energy Transmission Grating Spectrometer (HETGS) observations collected in a multi-wavelength campaign with UV data using the Hubble Space Telescope Cosmic Origins Spectrograph (HST-COS) and radio bands using the Jansky Very Large Array (VLA). We constructed a multi-wavelength ionizing spectral energy distribution using these observations and archival infrared data to create XSTAR photoionization models specific to the PG 1211+143 flux behavior during the epoch of our observations. Our analysis of the Chandra-HETGS spectra yields complex absorption lines from H-like and He-like ions of Ne, Mg, and Si, which confirm the presence of an ultra-fast outflow (UFO) with a velocity of approximately - 17,300 km s(-1) (outflow redshift z(out) similar to -0.0561) in the rest frame of PG 1211+143. This absorber is well described by an ionization parameter log xi similar to 2.9 erg s-1 cm and column density logN(H) similar to 21.5 cm(-2). This corresponds to a stable region of the absorber's thermal stability curve, and furthermore its implied neutral hydrogen column is broadly consistent with a broad Lya absorption line at a mean outflow velocity of approximately -16,980 km s(-1) detected by our HST-COS observations. Our findings represent the first simultaneous detection of a UFO in both X-ray and UV observations. Our VLA observations provide evidence for an active jet in PG 1211+143, which may be connected to the X-ray and UV outflows; this possibility can be evaluated using very-long-baseline interferometric observations.

Item Type:	Journal Article
Publication:	ASTROPHYSICAL JOURNAL
Additional Information:	Copy right for this article brlong to the IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	02 Mar 2018 14:53
Last Modified:	02 Mar 2018 14:53
URI:	http://eprints.iisc.ac.in/id/eprint/59044

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