THE SPITZER INFRARED SPECTROGRAPH DEBRIS DISK CATALOG. II. SILICATE FEATURE ANALYSIS OF UNRESOLVED TARGETS
THE SPITZER INFRARED SPECTROGRAPH DEBRIS DISK CATALOG. II. SILICATE FEATURE ANALYSIS OF UNRESOLVED TARGETS
复制标题
斯皮策红外光谱仪碎片盘目录。
DOI：
10.1088/0004-637x/798/2/87
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
C. Lisse
中科院分区：
文献类型：
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作者：
T. Mittal;Christine H. Chen;H. Jang;P. Manoj;B. Sargent;D. Watson;C. Lisse
在斯皮策太空望远镜的低温任务中，天文学家获得了红外光谱仪（IRS）对数百个候选碎片盘的观测结果，这些碎片盘已被汇编在斯皮策IRS碎片盘目录中。我们已经发现了目录中120个目标的10和/或20 μm硅酸盐发射特征，并模拟了这些源的IRS光谱，与MIPS 70 μm观测结果一致，假设颗粒由硅酸盐（橄榄石、辉石、橄榄石和辉辉石）组成，并且位于具有幂定律尺寸和表面密度分布的连续圆盘中，或者位于使用两个单独的尘埃颗粒温度进行表征的薄环中。对于更适合连续盘模型的系统，我们发现(1)尘埃粒度分布幂律指数与碰撞级联的预期值q = 3.5-4.0一致，有大量值超出该范围；(2)最小粒度amin随恒星光度L*的增加而增加，但amin对L*的依赖性弱于单独辐射压力的预期。此外，我们还发现(3)碎片盘中尘埃的结晶分数随时间的变化而变化，对于任何特定恒星年龄或质量的恒星，晶体分数的色散都很大；(4)磁盘内缘与宿主恒星质量相关；(5)scoc - cen中同时期磁盘的性质存在很大变化，表明观测到的变化可能是由于行星形成的随机性和多样性。
During the Spitzer Space Telescope cryogenic mission, astronomers obtained Infrared Spectrograph (IRS) observations of hundreds of debris disk candidates that have been compiled in the Spitzer IRS Debris Disk Catalog. We have discovered 10 and/or 20 μm silicate emission features toward 120 targets in the catalog and modeled the IRS spectra of these sources, consistent with MIPS 70 μm observations, assuming that the grains are composed of silicates (olivine, pyroxene, forsterite, and enstatite) and are located either in a continuous disk with power-law size and surface density distributions or thin rings that are well-characterized using two separate dust grain temperatures. For systems better fit by the continuous disk model, we find that (1) the dust size distribution power-law index is consistent with that expected from a collisional cascade, q = 3.5–4.0, with a large number of values outside this range, and (2) the minimum grain size, amin, increases with stellar luminosity, L*, but the dependence of amin on L* is weaker than expected from radiation pressure alone. In addition, we also find that (3) the crystalline fraction of dust in debris disks evolves as a function of time with a large dispersion in crystalline fractions for stars of any particular stellar age or mass, (4) the disk inner edge is correlated with host star mass, and (5) there exists substantial variation in the properties of coeval disks in Sco-Cen, indicating that the observed variation is probably due to stochasticity and diversity in planet formation.
DOI：
10.1088/0004-637x/691/2/l133
发表时间：
2009-02
期刊：
The Astrophysical Journal
影响因子：
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作者：
S. Stewart;Z. Leinhardt
通讯作者：
S. Stewart;Z. Leinhardt
F型恒星的多重性
DOI：
10.1088/0067-0049/203/2/30
发表时间：
2012
期刊：
The Astrophysical Journal Supplement Series
影响因子：
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作者：
Fuhrmann K;Chini R.
通讯作者：
Chini R.
Herschel/DUNES 中一类特殊的碎片盘
DOI：
10.1051/0004-6361/201118077
发表时间：
2012
期刊：
影响因子：
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作者：
S. Ertel;S. Wolf;J.P. Marshall;C. Eiroa;J.-C. Augereau
通讯作者：
J.-C. Augereau