X-ray observation of mars at solar minimum with Suzaku

Kumi Ishikawa; Yuichiro Ezoe; Takaya Ohashi; Naoki Terada; Yoshifumi Futaana

doi:10.1093/pasj/63.sp3.s705

X-ray observation of mars at solar minimum with Suzaku

Kumi Ishikawa, Yuichiro Ezoe, Takaya Ohashi, Naoki Terada, Yoshifumi Futaana

SCI - Geophysics

Research output: Contribution to journal › Article › peer-review

5 Citations (Scopus)

Abstract

Mars was observed in X-rays during 2008 April 3-5 for 82 ks with the Japanese Suzaku observatory. Mars has been known to emit X-rays via the scattering of solar X-rays and via charge exchange between neutral atoms in the exosphere and solar-wind ions. Past theoretical studies suggest that the exospheric neutral density may vary by a factor of up to 10 over the solar cycle. To investigate a potential change of the exospheric charge exchange emission, Mars was observed with Suzaku at solar minimum. Significant signals were not detected at the position of Mars in the energy band of 0.2-5 keV. The 2 σ upper limit of the OVII line flux in 0.5-0.65 keV was 4.3 × 10^-5 photonscm^-2 s^-1. Comparing this upper limit to past Chandra and XMM-Newton observations conducted near solar maximum, it was found that the exospheric density at solar minimum does not exceed that near solar maximum by more than 6-70 times.

Original language	English
Pages (from-to)	S705-S712
Journal	Publications of the Astronomical Society of Japan
Volume	63
Issue number	SPEC. ISSUE 3
DOIs	https://doi.org/10.1093/pasj/63.sp3.s705
Publication status	Published - 2011 Nov 25

Keywords

Planets and satellites: Individual (Mars)
X-rays: Individual (Mars)

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1093/pasj/63.sp3.s705

Cite this

@article{b1bf5f937757413f8a4bc8d1b360896d,

title = "X-ray observation of mars at solar minimum with Suzaku",

abstract = "Mars was observed in X-rays during 2008 April 3-5 for 82 ks with the Japanese Suzaku observatory. Mars has been known to emit X-rays via the scattering of solar X-rays and via charge exchange between neutral atoms in the exosphere and solar-wind ions. Past theoretical studies suggest that the exospheric neutral density may vary by a factor of up to 10 over the solar cycle. To investigate a potential change of the exospheric charge exchange emission, Mars was observed with Suzaku at solar minimum. Significant signals were not detected at the position of Mars in the energy band of 0.2-5 keV. The 2 σ upper limit of the OVII line flux in 0.5-0.65 keV was 4.3 × 10-5 photonscm-2 s-1. Comparing this upper limit to past Chandra and XMM-Newton observations conducted near solar maximum, it was found that the exospheric density at solar minimum does not exceed that near solar maximum by more than 6-70 times.",

keywords = "Planets and satellites: Individual (Mars), X-rays: Individual (Mars)",

author = "Kumi Ishikawa and Yuichiro Ezoe and Takaya Ohashi and Naoki Terada and Yoshifumi Futaana",

year = "2011",

month = nov,

day = "25",

doi = "10.1093/pasj/63.sp3.s705",

language = "English",

volume = "63",

pages = "S705--S712",

journal = "Publications of the Astronomical Society of Japan",

issn = "0004-6264",

publisher = "Astronomical Society of Japan",

number = "SPEC. ISSUE 3",

}

TY - JOUR

T1 - X-ray observation of mars at solar minimum with Suzaku

AU - Ishikawa, Kumi

AU - Ezoe, Yuichiro

AU - Ohashi, Takaya

AU - Terada, Naoki

AU - Futaana, Yoshifumi

PY - 2011/11/25

Y1 - 2011/11/25

N2 - Mars was observed in X-rays during 2008 April 3-5 for 82 ks with the Japanese Suzaku observatory. Mars has been known to emit X-rays via the scattering of solar X-rays and via charge exchange between neutral atoms in the exosphere and solar-wind ions. Past theoretical studies suggest that the exospheric neutral density may vary by a factor of up to 10 over the solar cycle. To investigate a potential change of the exospheric charge exchange emission, Mars was observed with Suzaku at solar minimum. Significant signals were not detected at the position of Mars in the energy band of 0.2-5 keV. The 2 σ upper limit of the OVII line flux in 0.5-0.65 keV was 4.3 × 10-5 photonscm-2 s-1. Comparing this upper limit to past Chandra and XMM-Newton observations conducted near solar maximum, it was found that the exospheric density at solar minimum does not exceed that near solar maximum by more than 6-70 times.

AB - Mars was observed in X-rays during 2008 April 3-5 for 82 ks with the Japanese Suzaku observatory. Mars has been known to emit X-rays via the scattering of solar X-rays and via charge exchange between neutral atoms in the exosphere and solar-wind ions. Past theoretical studies suggest that the exospheric neutral density may vary by a factor of up to 10 over the solar cycle. To investigate a potential change of the exospheric charge exchange emission, Mars was observed with Suzaku at solar minimum. Significant signals were not detected at the position of Mars in the energy band of 0.2-5 keV. The 2 σ upper limit of the OVII line flux in 0.5-0.65 keV was 4.3 × 10-5 photonscm-2 s-1. Comparing this upper limit to past Chandra and XMM-Newton observations conducted near solar maximum, it was found that the exospheric density at solar minimum does not exceed that near solar maximum by more than 6-70 times.

KW - Planets and satellites: Individual (Mars)

KW - X-rays: Individual (Mars)

UR - http://www.scopus.com/inward/record.url?scp=82555200902&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=82555200902&partnerID=8YFLogxK

U2 - 10.1093/pasj/63.sp3.s705

DO - 10.1093/pasj/63.sp3.s705

M3 - Article

AN - SCOPUS:82555200902

VL - 63

SP - S705-S712

JO - Publications of the Astronomical Society of Japan

JF - Publications of the Astronomical Society of Japan

SN - 0004-6264

IS - SPEC. ISSUE 3

ER -

X-ray observation of mars at solar minimum with Suzaku

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this