Top-heavy integrated galactic stellar initial mass functions in starbursts
Top-heavy integrated galactic stellar initial mass functions in starbursts
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星暴中头重脚轻的综合星系恒星初始质量函数
DOI：
10.1111/j.1365-2966.2010.17959.x
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发表时间：
2010
影响因子：
4.8
通讯作者：
J. Pflamm
中科院分区：
文献类型：
--
作者：
C. Weidner;P. Kroupa;J. Pflamm
在极端的星暴中观测到大于1000 Myr−1的恒星形成速率（SFRs）。这导致了质量为>10 6 Min的星团的形成，恒星前核心的拥挤可能导致恒星初始质量函数（IMF）的变化。事实上，超紧凑矮星系的大质量光比和最近对球状星团的研究结果表明，随着恒星形成密度的增加，IMF会变得头重头轻。我们探索了这些非常大质量和紧凑系统中头重头轻的IMF对星系初始质量函数（IGIMF）的影响，IGIMF是星系范围内的IMF，依赖于星系的SFR。对于质量大于1 m的恒星，所得的igimf斜率α3在1.5到Salpeter斜率2.3之间，嵌入星团质量函数（ECMF）斜率（β）为2.0，但前提是ECMF在主要恒星爆发的星系中没有低质量星团。或者，β必须随着SFR的增加而减小，使得具有主要恒星爆发的星系具有头重头轻的ECMF。由此产生的igimf在观测推断的IMF随红移的变化范围内。
Star formation rates (SFRs) larger than 1000 Myr −1 are observed in extreme starbursts. This leads to the formation of star clusters with masses >10 6 Min which crowding of the pre-stellar cores may lead to a change of the stellar initial mass function (IMF). Indeed, the large mass-to-light ratios of ultracompact dwarf galaxies and recent results on globular clusters suggest the IMF to become top-heavy with increasing star-forming density. We explore the implications of top-heavy IMFs in these very massive and compact systems for the integrated galactic initial mass function (IGIMF), which is the galaxy-wide IMF, in dependence of the SFR of galaxies. The resulting IGIMFs can have slopes, α3, for stars more massive than about 1 Mbetween 1.5 and the Salpeter slope of 2.3 for an embedded cluster mass function (ECMF) slope (β) of 2.0, but only if the ECMF has no low-mass clusters in galaxies with major starbursts. Alternatively, β would have to decrease with increasing SFR > 10 Myr −1 such that galaxies with major starbursts have a top-heavy ECMF. The resulting IGIMFs are within the range of observationally deduced IMF variations with redshift.
DOI：
10.1088/0004-637x/720/1/226
发表时间：
2010-09
期刊：
The Astrophysical Journal
影响因子：
--
作者：
P. Papadopoulos
通讯作者：
P. Papadopoulos
球状星团 - 星系指南
DOI：
10.1007/978-3-540-76961-3
发表时间：
2009
期刊：
影响因子：
--
作者：
Fiestas J;Spurzem R.
通讯作者：
Spurzem R.