Revealing the location and structure of the accretion disk-wind in PDS456
We present evidence for the rapid variability of the high velocity iron K-shell absorption in the nearby ($z=0.184$) quasar PDS456. From a recent long Suzaku observation in 2013 ($\sim1$Ms effective duration) we find that the the equivalent width of iron K absorption increases by a factor of $\sim5$...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
Institute of Physics Publishing
2014
|
| _version_ | 1797106368999587840 |
|---|---|
| author | Gofford, J Reeves, J Braito, V Nardini, E Costa, M Matzeu, M O'Brien, P Ward, M Turner, T Miller, L |
| author_facet | Gofford, J Reeves, J Braito, V Nardini, E Costa, M Matzeu, M O'Brien, P Ward, M Turner, T Miller, L |
| author_sort | Gofford, J |
| collection | OXFORD |
| description | We present evidence for the rapid variability of the high velocity iron K-shell absorption in the nearby ($z=0.184$) quasar PDS456. From a recent long Suzaku observation in 2013 ($\sim1$Ms effective duration) we find that the the equivalent width of iron K absorption increases by a factor of $\sim5$ during the observation, increasing from $<105$eV within the first 100ks of the observation, towards a maximum depth of $\sim500$eV near the end. The implied outflow velocity of $\sim0.25$c is consistent with that claimed from earlier (2007, 2011) Suzaku observations. The absorption varies on time-scales as short as $\sim1$ week. We show that this variability can be equally well attributed to either (i) an increase in column density, plausibly associated with a clumpy time-variable outflow, or (ii) the decreasing ionization of a smooth homogeneous outflow which is in photo-ionization equilibrium with the local photon field. The variability allows a direct measure of absorber location, which is constrained to within $r=200-3500$$\rm{r_{g}}$ of the black hole. Even in the most conservative case the kinetic power of the outflow is $\gtrsim6\%$ of the Eddington luminosity, with a mass outflow rate in excess of $\sim40\%$ of the Eddington accretion rate. The wind momentum rate is directly equivalent to the Eddington momentum rate which suggests that the flow may have been accelerated by continuum-scattering during an episode of Eddington-limited accretion. |
| first_indexed | 2024-03-07T07:00:37Z |
| format | Journal article |
| id | oxford-uuid:ffa010ad-1970-4cbc-bf18-d10f688370c1 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:00:37Z |
| publishDate | 2014 |
| publisher | Institute of Physics Publishing |
| record_format | dspace |
| spelling | oxford-uuid:ffa010ad-1970-4cbc-bf18-d10f688370c12022-03-27T13:46:20ZRevealing the location and structure of the accretion disk-wind in PDS456Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ffa010ad-1970-4cbc-bf18-d10f688370c1EnglishSymplectic Elements at OxfordInstitute of Physics Publishing2014Gofford, JReeves, JBraito, VNardini, ECosta, MMatzeu, MO'Brien, PWard, MTurner, TMiller, LWe present evidence for the rapid variability of the high velocity iron K-shell absorption in the nearby ($z=0.184$) quasar PDS456. From a recent long Suzaku observation in 2013 ($\sim1$Ms effective duration) we find that the the equivalent width of iron K absorption increases by a factor of $\sim5$ during the observation, increasing from $<105$eV within the first 100ks of the observation, towards a maximum depth of $\sim500$eV near the end. The implied outflow velocity of $\sim0.25$c is consistent with that claimed from earlier (2007, 2011) Suzaku observations. The absorption varies on time-scales as short as $\sim1$ week. We show that this variability can be equally well attributed to either (i) an increase in column density, plausibly associated with a clumpy time-variable outflow, or (ii) the decreasing ionization of a smooth homogeneous outflow which is in photo-ionization equilibrium with the local photon field. The variability allows a direct measure of absorber location, which is constrained to within $r=200-3500$$\rm{r_{g}}$ of the black hole. Even in the most conservative case the kinetic power of the outflow is $\gtrsim6\%$ of the Eddington luminosity, with a mass outflow rate in excess of $\sim40\%$ of the Eddington accretion rate. The wind momentum rate is directly equivalent to the Eddington momentum rate which suggests that the flow may have been accelerated by continuum-scattering during an episode of Eddington-limited accretion. |
| spellingShingle | Gofford, J Reeves, J Braito, V Nardini, E Costa, M Matzeu, M O'Brien, P Ward, M Turner, T Miller, L Revealing the location and structure of the accretion disk-wind in PDS456 |
| title | Revealing the location and structure of the accretion disk-wind in
PDS456 |
| title_full | Revealing the location and structure of the accretion disk-wind in
PDS456 |
| title_fullStr | Revealing the location and structure of the accretion disk-wind in
PDS456 |
| title_full_unstemmed | Revealing the location and structure of the accretion disk-wind in
PDS456 |
| title_short | Revealing the location and structure of the accretion disk-wind in
PDS456 |
| title_sort | revealing the location and structure of the accretion disk wind in pds456 |
| work_keys_str_mv | AT goffordj revealingthelocationandstructureoftheaccretiondiskwindinpds456 AT reevesj revealingthelocationandstructureoftheaccretiondiskwindinpds456 AT braitov revealingthelocationandstructureoftheaccretiondiskwindinpds456 AT nardinie revealingthelocationandstructureoftheaccretiondiskwindinpds456 AT costam revealingthelocationandstructureoftheaccretiondiskwindinpds456 AT matzeum revealingthelocationandstructureoftheaccretiondiskwindinpds456 AT obrienp revealingthelocationandstructureoftheaccretiondiskwindinpds456 AT wardm revealingthelocationandstructureoftheaccretiondiskwindinpds456 AT turnert revealingthelocationandstructureoftheaccretiondiskwindinpds456 AT millerl revealingthelocationandstructureoftheaccretiondiskwindinpds456 |