The variable Xray spectrum of PDS 456 and

The variable X-ray spectrum of PDS 456 and High-Velocity Outflows Shai Kaspi Technion – Haifa; Tel-Aviv University Israel & Ehud Behar, James Reeves O’Brien P. T, Ward M. , Braito V. , Fabian A. , Miller L. , Mushotzky R. , Turner T. J. “The X-ray Universe 2008” – Granada, Spain – 29 May 2008

Outline - High-velocity mass outflows in AGNs - New data and first results of the varying spectrum of PDS 456 - Varying spectrum of PG 1211+143 - Summary

Mass Outflow From AGNs Does mass outflow from AGNs? • Collimated jets and/or lobs in “Radio loud” quasars – 5%-10% of quasars are “Radio loud”. • Broad absorption lines (BALs) – Blueshifted up to 0. 1 c - UV lines of ~10% “radio quiet” quasars. Is mass loss an important component in most AGNs? Past decade UV (HST) and X-ray (XMM & Chandra) observations detected outflowing mass (velocities of several hundreds km/s) in the majority of moderate luminosity Seyfert galaxies (~70%), indicating the importance of mass outflow.

Mass outflow • How much mass is carried out of the AGN by the outflow? • How does it compared to the amount of matter being accreted? • Does the ionized outflow carry a significant fraction of the energy output of the AGN? Answers are currently model dependent

Mass outflow in low-luminosity AGNs Outflows can provide key results about AGNs’ central regions, e. g. : • Dynamics: outflows velocities of several 100 km/s in multiple components. • Range of ionization parameters UOxygen ~ 0. 01 to 1 (degeneracy of location and density). • Column density ~ 1021 -23 cm-2. • Normal outflows are not very significant in terms of energy as the outflow is of ~ 0. 1 -5 M yr-1. High-velocity mass outflows are potentially energetically significant.

High-Velocity Outflows UV BAL LEdd /L (km/s) Source Vout [c] NH [1023 cm-2] APM 08279+5255 0. 2 , 0. 4 1 ± 0. 5 (12. 4 k)Y ~ 0. 04 c high 5 N 1. 1 0. 1 ± 0. 05, 6. 9 (? )Y 0. 7 4 N 0. 3 0. 16 5 Y(? ~12 k) 1. 0 0. 14 N >0. 5 Chartas et al. (2002) PG 1211+143 0. 08 - 0. 1 Pounds et al. (2003, 2006) PG 1115+080 Chartas et al. (2003, 2007) 0. 1 , 0. 34 PG 0844+349 0. 2 - 0. 26 Pounds et al. (2003) PDS 456 Reeves et al. (2003) IC 4329 A Markowitz et al. (2006) Mass outflow of several M yr-1

PDS 456 The most luminous radio-quiet type I quasar in the nearby Universe Discovered a decade ago (Torres 1997) Z=0. 184 LBol ~ 1047 erg/sec NH(Galactic)=2 X 1021 cm-2

RXTE light curve Two main flux states: high and low

XMM observation 2001 Feb 26 - 40 Ks Reeves, O'Brien, Ward (2003) EPIC spectra show soft excess and a deep absorption trough around 7 ke. V which if interpreted as Fe K-Shell absorption edges is an outflow at ~50000 km/sec. RGS spectra show deep absorption around 1 ke. V which if interpreted as a blend Fe L-shell absorption is an outflow at ~50000 km/sec.

Chandra Observation 2003 May 7 – 145 ks 40 ks 145 ks Chandra/HETGS observation two years after the XMM one. PDS 456 is in a low state and hardly any features can be detected.

Two more XMM Observations Behar et al. in prep. Spectral variability over 1 -2 days

EPIC-pn image - 2007

Problem with background in 2007 Background . Source + Background Source - Background is showing strong narrow fluorescence emission lines due to Ka of Al, Ni, Cu, and Zn from the CCD structure. Source+Background does not show these lines as the center of the CCD is free of these lines. Source-Background will indicate a false absorption line at ~8 ke. V.

No Problem with background of 2001. The background of the 2001 observation does not show the narrow emission lines. . The deficit in flux around 8 ke. V is not caused by the background lines

XMM 2001 and 2007 comparison Behar et al. in prep. Strong variability over 6 years. Also spectral variability over 2 days.

RGS spectra Behar et al. in prep. Variability over 1 -2 days – however features are not identified

L-shell absorption region Behar et al. in prep. 2007 observations do not show same absorption feature from 2001

Suzaku – 2007 -2 -24 - 370 ks Fe absorption line Black – Suzaku 2007 ; Red – XMM-Newton 2001 Fe XXVI 1 s-2 p 6. 97 ke. V Reeves et al. in prep. If the detected absorption is the Fe XXVI line then the outflows are at 0. 26 c and 0. 31 c

Spectra comparison from 2001 to 2007 XMM 2001 Suzaku 2007 G=2. 3 Chandra 2003 G=1. 3 Ratio of spectra to a G=2 power law illustrating the drastic long term spectral variability

O VIII RGS O VIII EPIC-pn O VII PG 1211+143 Pounds, Reeves et al. (2003) claim to detect an outflow of at ~ 0. 1 c. NH ~ 1024 cm-2 S XVI Fe XXVI Kaspi & Behar (2006) gave alternative interpretation of an outflow at 3000 km/sec. NH ~ 1021. 5 cm-2 Two interpretations – differ by two orders of magnitude in the outflowing mass

PG 1211+143 Two RGS observations 2001 -06 -15 2004 -06 -21 Spectra are generally consistent, but a bit different slope and some different details. Object varied in time or a result of the poor S/N

Simultaneous XMM-Newton and Chandra Xmm-Newton/RGS and Chandra/LETGS spectra are consistent overall, but differ in many details – probably a consequence of the poor S/N.

Three Chandra/LETGS observations PG 1211+143 doubled its luminosity in two days. Narrow line features does not reproduce in the different spectra.

Summary – What can we learn… • High-velocity outflows are not found in low-luminosity AGNs. • Several High-luminosity AGNs have high-velocity outflows, indicating mass outflow that can affect the surrounding host galaxy. • High-Velocity outflow are varying on time scales of days to years. • The causes of the variability is yet to be determine: - Changes in the covering factor of the absorber. - Changes in the column density of the absorber. - The absorber is moving fast in and out of the line of sight. • High-velocity mass outflow are potentially energetically significant but their variations and model dependent parameters cannot yet give a coherent picture. • If High-velocity outflows are a transit phenomenon this needs to be taken into account when calculating the effect of the mass outflow on the surrounding.