Revisiting the Local Leo Cold Cloud and revised constraints on the Local Hot Bubble
- NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
- University of California–Berkeley, Astronomy Department, Berkeley, CA 94720-0001 (United States)
- Université Versailles St-Quentin, Sorbonne Universités, UPMC Univ. Paris 06, CNRS/INSU, LATMOS-IPSL, 11 Boulevard d’Alembert, F-78280, Guyancourt (France)
- The Johns Hopkins University, The Henry A. Rowland Department of Physics and Astronomy, Baltimore, MD 21218 (United States)
- GEPI, Observatoire de Paris, CNRS UMR8111, Université Paris Diderot, 5 Place Jules Janssen, F-92190 Meudon (France)
- University of Wisconsin–Madison, Department of Physics, 1150 University Avenue, Madison, WI 53706 (United States)
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21210 (United States)
The Local Leo Cold Cloud (LLCC, at a distance of 11–24 pc) was studied in its relation to the Local Hot Bubble (LHB) and the result suggested that much of the observed 1/4 keV emission in that direction originates in front of the cloud. This placed a strong constraint on the distribution of X-ray emission within the LHB and called into question the assumption of a uniform distribution of X-ray emitting plasma within the Local Cavity. However, recent work has quantified the contribution of heliospheric solar wind charge exchange (SWCX) emission to the diffuse X-ray background measured by the ROSAT All-Sky Survey (RASS) at 1/4 keV, and led to the consistency of pressure measurements between the LHB and the local cloud component of the complex of local interstellar clouds (CLICs) surrounding the Sun. In this paper we revisit the LLCC and improve the previous analysis by using higher resolution RASS data, a serendipitous ROSAT pointed observation, a rigorous treatment of the band-averaged X-ray absorption cross section, and models for the heliospheric and magnetospheric SWCX contributions. We find that the foreground emission to the cloud is in excess of the expected heliospheric (interplanetary plus near Earth) SWCX contribution but that it is marginally consistent with the range of possible LHB plasma path lengths between the LLCC and the CLICs given the currently understood plasma emissivity.
- OSTI ID:
- 22883052
- Journal Information:
- Astrophysical Journal, Vol. 806, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Since 2009, the country of publication for this journal is the UK.; ISSN 0004-637X
- Country of Publication:
- United Kingdom
- Language:
- English
Similar Records
THE SOLAR WIND CHARGE-TRANSFER X-RAY EMISSION IN THE 1/4 keV ENERGY RANGE: INFERENCES ON LOCAL BUBBLE HOT GAS AT LOW Z
PRESSURE EQUILIBRIUM BETWEEN THE LOCAL INTERSTELLAR CLOUDS AND THE LOCAL HOT BUBBLE