Exploring the case for hard-X-ray beaming in NGC 6946 X-1

In order to understand the nature of super-Eddington accretion we must explore both the emission emerging directly from the inflow and its impact on the surroundings. In this paper, we test whether we can use the optical line emission of spatially resolved, ionized nebulae around ultraluminous X-ray...

Full description

Bibliographic Details
Main Authors: Beuchert, T., Middleton, M.J., Soria, R., Miller-Jones, James, Dauser, T., Roberts, T.P., Sathyaprakash, R., Markoff, S.
Format: Journal Article
Published: 2024
Online Access:http://purl.org/au-research/grants/arc/DP200102471
http://hdl.handle.net/20.500.11937/97225
_version_ 1848766241917894656
author Beuchert, T.
Middleton, M.J.
Soria, R.
Miller-Jones, James
Dauser, T.
Roberts, T.P.
Sathyaprakash, R.
Markoff, S.
author_facet Beuchert, T.
Middleton, M.J.
Soria, R.
Miller-Jones, James
Dauser, T.
Roberts, T.P.
Sathyaprakash, R.
Markoff, S.
author_sort Beuchert, T.
building Curtin Institutional Repository
collection Online Access
description In order to understand the nature of super-Eddington accretion we must explore both the emission emerging directly from the inflow and its impact on the surroundings. In this paper, we test whether we can use the optical line emission of spatially resolved, ionized nebulae around ultraluminous X-ray sources (ULXs) as a proxy for their X-ray luminosity. We choose the ULX NGC 6946 X-1 and its nebula, MF16, as a test case. By studying how the nebular optical line emission responds to assumed irradiation, we can infer the degree to which we require the UV or X-ray emission from the inflow to be collimated by optically thick winds seemingly ubiquitously associated with ULXs. We find that the nebula is highly sensitive to compact UV emission but mostly insensitive to hard X-rays. Our attempts to quantify the beaming of the soft and hard X-rays therefore strongly depends on the UV luminosity of the ULX in the centre of the nebula. We find that it is not possible to conclude a lack of geometrical beaming of hard X-rays from such sources via nebula feedback.
first_indexed 2025-11-14T11:48:01Z
format Journal Article
id curtin-20.500.11937-97225
institution Curtin University Malaysia
institution_category Local University
last_indexed 2025-11-14T11:48:01Z
publishDate 2024
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-972252025-04-30T01:39:49Z Exploring the case for hard-X-ray beaming in NGC 6946 X-1 Beuchert, T. Middleton, M.J. Soria, R. Miller-Jones, James Dauser, T. Roberts, T.P. Sathyaprakash, R. Markoff, S. In order to understand the nature of super-Eddington accretion we must explore both the emission emerging directly from the inflow and its impact on the surroundings. In this paper, we test whether we can use the optical line emission of spatially resolved, ionized nebulae around ultraluminous X-ray sources (ULXs) as a proxy for their X-ray luminosity. We choose the ULX NGC 6946 X-1 and its nebula, MF16, as a test case. By studying how the nebular optical line emission responds to assumed irradiation, we can infer the degree to which we require the UV or X-ray emission from the inflow to be collimated by optically thick winds seemingly ubiquitously associated with ULXs. We find that the nebula is highly sensitive to compact UV emission but mostly insensitive to hard X-rays. Our attempts to quantify the beaming of the soft and hard X-rays therefore strongly depends on the UV luminosity of the ULX in the centre of the nebula. We find that it is not possible to conclude a lack of geometrical beaming of hard X-rays from such sources via nebula feedback. 2024 Journal Article http://hdl.handle.net/20.500.11937/97225 10.1093/mnras/stae1975 http://purl.org/au-research/grants/arc/DP200102471 fulltext
spellingShingle Beuchert, T.
Middleton, M.J.
Soria, R.
Miller-Jones, James
Dauser, T.
Roberts, T.P.
Sathyaprakash, R.
Markoff, S.
Exploring the case for hard-X-ray beaming in NGC 6946 X-1
title Exploring the case for hard-X-ray beaming in NGC 6946 X-1
title_full Exploring the case for hard-X-ray beaming in NGC 6946 X-1
title_fullStr Exploring the case for hard-X-ray beaming in NGC 6946 X-1
title_full_unstemmed Exploring the case for hard-X-ray beaming in NGC 6946 X-1
title_short Exploring the case for hard-X-ray beaming in NGC 6946 X-1
title_sort exploring the case for hard-x-ray beaming in ngc 6946 x-1
url http://purl.org/au-research/grants/arc/DP200102471
http://hdl.handle.net/20.500.11937/97225