Abstract
The solar neighbourhood is the closest and most easily studied sample of the Galactic interstellar medium, an understanding of which is essential formodels of star formation and galaxy evolution.Observations of an unexpectedly intense diffuse flux of easily absorbed 1/4-kiloelectronvolt X-rays 1,2, coupled with the discovery that interstellar space within about a hundredparsecs of the Sun is almost completely devoid of cool absorbing gas3, led to a picture of a 'local cavity' filled with X-ray-emitting hot gas, dubbed the local hot bubble4-6. This model was recently challenged by suggestions that the emission could instead be readily produced within the Solar System by heavy solar-wind ions exchanging electrons with neutralHandHein interplanetary space7-11, potentially removing themajor piece of evidence for the local existence of million-degree gas within the Galactic disk12-15. Here we report observations showing that the total solarwind charge-exchange contribution is approximately 40 per cent of the 1/4-keV flux in the Galactic plane. The fact that the measured flux is not dominated by charge exchange supports the notion of a million-degree hot bubble extending about a hundred parsecs from the Sun.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 171-173 |
| Number of pages | 3 |
| Journal | Nature |
| Volume | 512 |
| Issue number | 7513 |
| DOIs | |
| State | Published - Aug 14 2014 |
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The origin of the local 1/4-keV X-ray flux in both charge exchange and a hot bubble. / Galeazzi, Massimiliano; Chiao, M.; Collier, M. R.; Cravens, T.; Koutroumpa, D.; Kuntz, K. D.; Lallement, R.; Lepri, S. T.; McCammon, D.; Morgan, K.; Porter, F. S.; Robertson, I. P.; Snowden, S. L.; Thomas, N. E.; Uprety, Y.; Ursino, E.; Walsh, B. M.
In: Nature, Vol. 512, No. 7513, 14.08.2014, p. 171-173.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The origin of the local 1/4-keV X-ray flux in both charge exchange and a hot bubble
AU - Galeazzi, Massimiliano
AU - Chiao, M.
AU - Collier, M. R.
AU - Cravens, T.
AU - Koutroumpa, D.
AU - Kuntz, K. D.
AU - Lallement, R.
AU - Lepri, S. T.
AU - McCammon, D.
AU - Morgan, K.
AU - Porter, F. S.
AU - Robertson, I. P.
AU - Snowden, S. L.
AU - Thomas, N. E.
AU - Uprety, Y.
AU - Ursino, E.
AU - Walsh, B. M.
PY - 2014/8/14
Y1 - 2014/8/14
N2 - The solar neighbourhood is the closest and most easily studied sample of the Galactic interstellar medium, an understanding of which is essential formodels of star formation and galaxy evolution.Observations of an unexpectedly intense diffuse flux of easily absorbed 1/4-kiloelectronvolt X-rays 1,2, coupled with the discovery that interstellar space within about a hundredparsecs of the Sun is almost completely devoid of cool absorbing gas3, led to a picture of a 'local cavity' filled with X-ray-emitting hot gas, dubbed the local hot bubble4-6. This model was recently challenged by suggestions that the emission could instead be readily produced within the Solar System by heavy solar-wind ions exchanging electrons with neutralHandHein interplanetary space7-11, potentially removing themajor piece of evidence for the local existence of million-degree gas within the Galactic disk12-15. Here we report observations showing that the total solarwind charge-exchange contribution is approximately 40 per cent of the 1/4-keV flux in the Galactic plane. The fact that the measured flux is not dominated by charge exchange supports the notion of a million-degree hot bubble extending about a hundred parsecs from the Sun.
AB - The solar neighbourhood is the closest and most easily studied sample of the Galactic interstellar medium, an understanding of which is essential formodels of star formation and galaxy evolution.Observations of an unexpectedly intense diffuse flux of easily absorbed 1/4-kiloelectronvolt X-rays 1,2, coupled with the discovery that interstellar space within about a hundredparsecs of the Sun is almost completely devoid of cool absorbing gas3, led to a picture of a 'local cavity' filled with X-ray-emitting hot gas, dubbed the local hot bubble4-6. This model was recently challenged by suggestions that the emission could instead be readily produced within the Solar System by heavy solar-wind ions exchanging electrons with neutralHandHein interplanetary space7-11, potentially removing themajor piece of evidence for the local existence of million-degree gas within the Galactic disk12-15. Here we report observations showing that the total solarwind charge-exchange contribution is approximately 40 per cent of the 1/4-keV flux in the Galactic plane. The fact that the measured flux is not dominated by charge exchange supports the notion of a million-degree hot bubble extending about a hundred parsecs from the Sun.
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U2 - 10.1038/nature13525
DO - 10.1038/nature13525
M3 - Article
VL - 512
SP - 171
EP - 173
JO - Nature
JF - Nature
SN - 0028-0836
IS - 7513
ER -