MARKARIAN 6: SHOCKING THE ENVIRONMENT OF AN INTERMEDIATE SEYFERT
Markarian 6 is a nearby (D ~ 78 Mpc) Seyfert 1.5, early-type galaxy, with a double set of radio bubbles. The outer set spans ~7.5 kpc and is expanding into the halo regions of the host galaxy. We present an analysis of our new Chandra observation, together with archival XMM-Newton data, to look for...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2015
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| Online Access: | http://hdl.handle.net/1721.1/95729 |
| _version_ | 1810993447576797184 |
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| author | Mingo, B. Hardcastle, M. J. Croston, J. H. Hota, A. Kharb, Preeti Kraft, Ralph P. Evans, Daniel A. |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Mingo, B. Hardcastle, M. J. Croston, J. H. Hota, A. Kharb, Preeti Kraft, Ralph P. Evans, Daniel A. |
| author_sort | Mingo, B. |
| collection | MIT |
| description | Markarian 6 is a nearby (D ~ 78 Mpc) Seyfert 1.5, early-type galaxy, with a double set of radio bubbles. The outer set spans ~7.5 kpc and is expanding into the halo regions of the host galaxy. We present an analysis of our new Chandra observation, together with archival XMM-Newton data, to look for evidence of emission from shocked gas around the external radio bubbles, both from spatially resolved regions in Chandra and from spectral analysis of the XMM-Newton data. We also look for evidence of a variable absorbing column along our line of sight to Mrk 6, to explain the evident differences seen in the active galactic nucleus (AGN) spectra from the various, non-contemporaneous, observations. We find that the variable absorption hypothesis explains the differences between the Chandra and XMM-Newton spectra, with the Chandra spectrum being heavily absorbed. The intrinsic N [subscript H] varies from ~8 × 10[superscript 21] atoms cm[superscript –2] to ~3 × 10[superscript 23] atoms cm[superscript –2] on short timescales (2-6 years). The past evolution of the source suggests this is probably caused by a clump of gas close to the central AGN, passing in front of us at the moment of the observation. Shells of thermal X-ray emission are detected around the radio bubbles, with a temperature of ~0.9 keV. We estimate a temperature of ~0.2 keV for the external medium using luminosity constraints from our Chandra image. We analyze these results using the Rankine-Hugoniot shock jump conditions, and obtain a Mach number of ~3.9, compatible with a scenario in which the gas in the shells is inducing a strong shock in the surrounding interstellar medium (ISM). This could be the third clear detection of strong shocks produced by a radio-powerful Seyfert galaxy. These results are compatible with previous findings on Centaurus A and NGC 3801, supporting a picture in which these AGN-driven outflows play an important role in the environment and evolution of the host galaxy. |
| first_indexed | 2024-09-23T13:25:38Z |
| format | Article |
| id | mit-1721.1/95729 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:25:38Z |
| publishDate | 2015 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/957292022-09-28T14:05:30Z MARKARIAN 6: SHOCKING THE ENVIRONMENT OF AN INTERMEDIATE SEYFERT Mingo, B. Hardcastle, M. J. Croston, J. H. Hota, A. Kharb, Preeti Kraft, Ralph P. Evans, Daniel A. MIT Kavli Institute for Astrophysics and Space Research Evans, Daniel A. Markarian 6 is a nearby (D ~ 78 Mpc) Seyfert 1.5, early-type galaxy, with a double set of radio bubbles. The outer set spans ~7.5 kpc and is expanding into the halo regions of the host galaxy. We present an analysis of our new Chandra observation, together with archival XMM-Newton data, to look for evidence of emission from shocked gas around the external radio bubbles, both from spatially resolved regions in Chandra and from spectral analysis of the XMM-Newton data. We also look for evidence of a variable absorbing column along our line of sight to Mrk 6, to explain the evident differences seen in the active galactic nucleus (AGN) spectra from the various, non-contemporaneous, observations. We find that the variable absorption hypothesis explains the differences between the Chandra and XMM-Newton spectra, with the Chandra spectrum being heavily absorbed. The intrinsic N [subscript H] varies from ~8 × 10[superscript 21] atoms cm[superscript –2] to ~3 × 10[superscript 23] atoms cm[superscript –2] on short timescales (2-6 years). The past evolution of the source suggests this is probably caused by a clump of gas close to the central AGN, passing in front of us at the moment of the observation. Shells of thermal X-ray emission are detected around the radio bubbles, with a temperature of ~0.9 keV. We estimate a temperature of ~0.2 keV for the external medium using luminosity constraints from our Chandra image. We analyze these results using the Rankine-Hugoniot shock jump conditions, and obtain a Mach number of ~3.9, compatible with a scenario in which the gas in the shells is inducing a strong shock in the surrounding interstellar medium (ISM). This could be the third clear detection of strong shocks produced by a radio-powerful Seyfert galaxy. These results are compatible with previous findings on Centaurus A and NGC 3801, supporting a picture in which these AGN-driven outflows play an important role in the environment and evolution of the host galaxy. 2015-02-27T16:16:57Z 2015-02-27T16:16:57Z 2011-03 2010-08 Article http://purl.org/eprint/type/JournalArticle 0004-637X 1538-4357 http://hdl.handle.net/1721.1/95729 Mingo, B., M. J. Hardcastle, J. H. Croston, D. A. Evans, A. Hota, P. Kharb, and R. P. Kraft. “MARKARIAN 6: SHOCKING THE ENVIRONMENT OF AN INTERMEDIATE SEYFERT.” The Astrophysical Journal 731, no. 1 (March 18, 2011): 21. © 2011 The American Astronomical Society en_US http://dx.doi.org/10.1088/0004-637x/731/1/21 The Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing American Astronomical Society |
| spellingShingle | Mingo, B. Hardcastle, M. J. Croston, J. H. Hota, A. Kharb, Preeti Kraft, Ralph P. Evans, Daniel A. MARKARIAN 6: SHOCKING THE ENVIRONMENT OF AN INTERMEDIATE SEYFERT |
| title | MARKARIAN 6: SHOCKING THE ENVIRONMENT OF AN INTERMEDIATE SEYFERT |
| title_full | MARKARIAN 6: SHOCKING THE ENVIRONMENT OF AN INTERMEDIATE SEYFERT |
| title_fullStr | MARKARIAN 6: SHOCKING THE ENVIRONMENT OF AN INTERMEDIATE SEYFERT |
| title_full_unstemmed | MARKARIAN 6: SHOCKING THE ENVIRONMENT OF AN INTERMEDIATE SEYFERT |
| title_short | MARKARIAN 6: SHOCKING THE ENVIRONMENT OF AN INTERMEDIATE SEYFERT |
| title_sort | markarian 6 shocking the environment of an intermediate seyfert |
| url | http://hdl.handle.net/1721.1/95729 |
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