期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 426, 期 3, 页码 1870-1883出版社
WILEY-BLACKWELL
DOI: 10.1111/j.1365-2966.2012.21831.x
关键词
galaxies: star formation; X-rays: binaries; X-rays: galaxies; X-rays: ISM
资金
- NASA [AR1-12008X]
- National Science Foundation
We study the emission from the hot interstellar medium (ISM) in a sample of nearby late-type galaxies defined in Paper I. Our sample covers a broad range of star formation rates (SFRs) from similar to 0.1 to similar to 17 M-circle dot yr(-1) and stellar masses from similar to 3 x 10(8) to similar to 6 x 10(10) M-circle dot. We take special care of systematic effects and contamination from bright and faint compact sources. We find that in all galaxies at least one optically thin thermal emission component is present in the unresolved emission, with the average temperature of < kT > = 0.24 keV. In about similar to 1/3 of galaxies, a second, higher temperature component is required, with < kT root = 0.71 keV. Although statistically significant variations in temperature between galaxies are present, we do not find any meaningful trends with the stellar mass or SFR of the host galaxy. The apparent luminosity of the diffuse emission in the 0.52 keV band linearly correlates with the SFR with the scale factor of L-X/SFR similar to 8.3 x 10(38) erg s(-1) (M-circle dot yr(-1))(-1), of which in average similar to 30-40 per cent is likely produced by faint compact sources of various types. We attempt to estimate the bolometric luminosity of the gas and obtain results differing by an order of magnitude, log(L-bol/SFR)similar to 39-40, depending on whether intrinsic absorption in star-forming galaxies is allowed or not. Our theoretically most accurate, but in practice the most model-dependent result for the intrinsic bolometric luminosity of the ISM is L-bol/SFR similar to 1.5 x 10(40) erg s(-1) (M-circle dot yr(-1))(-1). Assuming that core-collapse supernovae are the main source of energy, it is implied that epsilon(SN) similar to 5x10(-2)(E-SN/10(51))(-1) of mechanical energy of supernovae is converted into thermal energy of the ISM.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据