The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1

We present quasi-simultaneous, multi-epoch radio and X-ray measurements of Holmberg II X-1 using the European VLBI Network (EVN), the Karl G. Jansky Very Large Array (VLA), and the Chandra and Swift X-ray telescopes. The X-ray data show apparently hard spectra with steady X-ray luminosities four mon...

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Main Authors: Cseh, D., Miller-Jones, James, Jonker, P., Grisé, F., Paragi, Z., Corbel, S., Falcke, H., Frey, S., Kaaret, P., Körding, E.
Format: Journal Article
Published: Oxford University Press 2015
Online Access:http://purl.org/au-research/grants/arc/FT140101082
http://hdl.handle.net/20.500.11937/27472
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author Cseh, D.
Miller-Jones, James
Jonker, P.
Grisé, F.
Paragi, Z.
Corbel, S.
Falcke, H.
Frey, S.
Kaaret, P.
Körding, E.
author_facet Cseh, D.
Miller-Jones, James
Jonker, P.
Grisé, F.
Paragi, Z.
Corbel, S.
Falcke, H.
Frey, S.
Kaaret, P.
Körding, E.
author_sort Cseh, D.
building Curtin Institutional Repository
collection Online Access
description We present quasi-simultaneous, multi-epoch radio and X-ray measurements of Holmberg II X-1 using the European VLBI Network (EVN), the Karl G. Jansky Very Large Array (VLA), and the Chandra and Swift X-ray telescopes. The X-ray data show apparently hard spectra with steady X-ray luminosities four months apart from each other. In the high-resolution EVN radio observations, we have detected an extended milliarcsecond scale source with unboosted radio emission. The source emits non-thermal, likely optically thin synchrotron emission, and its morphology is consistent with a jet ejection. The 9-GHz VLA data show an arcsecond-scale triple structure of Holmberg II X-1 similar to that seen at lower frequencies. However, we find that the central ejection has faded by at least a factor of 7.3 over 1.5 yr. We estimate the dynamical age of the ejection to be higher than 2.1 yr. We show that such a rapid cooling can be explained with simple adiabatic expansion losses. These properties of Holmberg II X-1 imply that ULX radio bubbles may be inflated by ejecta instead of self-absorbed compact jets.
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spelling curtin-20.500.11937-274722022-11-23T06:38:06Z The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1 Cseh, D. Miller-Jones, James Jonker, P. Grisé, F. Paragi, Z. Corbel, S. Falcke, H. Frey, S. Kaaret, P. Körding, E. We present quasi-simultaneous, multi-epoch radio and X-ray measurements of Holmberg II X-1 using the European VLBI Network (EVN), the Karl G. Jansky Very Large Array (VLA), and the Chandra and Swift X-ray telescopes. The X-ray data show apparently hard spectra with steady X-ray luminosities four months apart from each other. In the high-resolution EVN radio observations, we have detected an extended milliarcsecond scale source with unboosted radio emission. The source emits non-thermal, likely optically thin synchrotron emission, and its morphology is consistent with a jet ejection. The 9-GHz VLA data show an arcsecond-scale triple structure of Holmberg II X-1 similar to that seen at lower frequencies. However, we find that the central ejection has faded by at least a factor of 7.3 over 1.5 yr. We estimate the dynamical age of the ejection to be higher than 2.1 yr. We show that such a rapid cooling can be explained with simple adiabatic expansion losses. These properties of Holmberg II X-1 imply that ULX radio bubbles may be inflated by ejecta instead of self-absorbed compact jets. 2015 Journal Article http://hdl.handle.net/20.500.11937/27472 10.1093/mnras/stv1308 http://purl.org/au-research/grants/arc/FT140101082 Oxford University Press fulltext
spellingShingle Cseh, D.
Miller-Jones, James
Jonker, P.
Grisé, F.
Paragi, Z.
Corbel, S.
Falcke, H.
Frey, S.
Kaaret, P.
Körding, E.
The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1
title The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1
title_full The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1
title_fullStr The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1
title_full_unstemmed The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1
title_short The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1
title_sort evolution of a jet ejection of the ultraluminous x-ray source holmberg ii x-1
url http://purl.org/au-research/grants/arc/FT140101082
http://hdl.handle.net/20.500.11937/27472