Discussion on “A Study on the Beginning of Secondary Compression of Soils” by R. G. Robinson

Mitchell, Dmr; Tewatia, Sudhir Kumar; Bose, P. R.

doi:10.1520/jte12577

Cited by 5 publications

(4 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some protostars show an obvious self-absorbed silicate feature at 10 µm (e.g., IRAS 04154+2823, 04181+2654 B; see Fig. 2d), where the silicate emission from inner disk regions is absorbed in cooler envelope regions, causing a feature that is more or less flat, with some emission and some absorption characteristics (Mitchell & Robinson 1981). The self-absorbed features probably indicate that the optical depth of the envelope along the line of sight is not as large as for the cases where a clear silicate absorption feature is seen.…”

Section: Irs Spectramentioning

confidence: 99%

SpitzerIRS Spectra and Envelope Models of Class I Protostars in Taurus

Furlan

McClure

Calvet

et al. 2008

ASTROPHYS J SUPPL S

110

152

View full text Add to dashboard Cite

We present Spitzer Infrared Spectrograph spectra of 28 Class I protostars in the Taurus star-forming region. The 5 to 36 µm spectra reveal excess emission from the inner regions of the envelope and accretion disk surrounding these predecessors of low-mass stars, as well as absorption features due to silicates and ices. Together with shorter-and longer-wavelength data from the literature, we construct spectral energy distributions and fit envelope models to 22 protostars of our sample, most of which are well-constrained due to the availability of the IRS spectra. We infer that the envelopes of the Class I objects in our sample cover a wide range in parameter space, particularly in density and centrifugal radius, implying different initial conditions for the collapse of protostellar cores.

show abstract

Section: Irs Spectramentioning

confidence: 99%

SpitzerIRS Spectra and Envelope Models of Class I Protostars in Taurus

Furlan

McClure

Calvet

et al. 2008

ASTROPHYS J SUPPL S

110

152

View full text Add to dashboard Cite

show abstract

“…This is a direct consequence of SK07 incorporating dust self-absorption in their models, an effect assigned to increasing quantities of dust at low temperatures (e.g. Mitchell & Robinson 1981), resulting in an overall shift of the far-IR peak to longer wavelengths. Our photometry misses the silicate feature so we cannot constrain its depth; nevertheless its varied strength in the models is consistent with observations as it is commonly found in LIRG & ULIRG spectra (e.g.…”

Section: Model Comparisonmentioning

confidence: 99%

The properties of 70 μm-selected high-redshift galaxies in the Extended Groth Strip

Symeonidis¹,

Willner²,

Rigopoulou³

et al. 2008

Monthly Notices RAS

View full text Add to dashboard Cite

We examine the infrared properties of 43 high‐redshift (0.1 < z < 1.2), infrared‐luminous galaxies in the Extended Groth Strip (EGS), selected by a deep 70 μm survey with the Multiband Imaging Photometer on Spitzer (MIPS). In addition and with reference to starburst‐type spectral energy distributions (SEDs), we derive a set of equations for estimating the total infrared luminosity (LIR) in the range 8–1000 μm using photometry from at least one MIPS band. 42 out of 43 of our sources' optical/infrared SEDs (λobserved < 160 μm) are starburst type, with only one object displaying a prominent power‐law near‐infrared continuum. For a quantitative analysis, models of radiation transfer in dusty media are fit on to the infrared photometry, revealing that the majority of galaxies are represented by high extinction, Av > 35, and for a large fraction (∼50 per cent) the SED turns over into the Rayleigh–Jeans regime at wavelengths longward of 90 μm. For comparison, we also fit semi‐empirical templates based on local galaxy data; however, these underestimate the far‐infrared SED shape by a factor of at least 2 and in extreme cases up to 10 for the majority (∼70 per cent) of the sources. Further investigation of SED characteristics reveals that the mid‐infrared (70/24 μm) continuum slope is decoupled from various galaxy properties such as the total infrared luminosity and far‐infrared peak, quantified by the L160/L70 ratio. In view of these results, we propose that these high‐redshift galaxies have different properties to their local counterparts, in the sense that large amounts of dust cause heavy obscuration and are responsible for an additional cold emissive component, appearing as a far‐infrared excess in their SEDs.

show abstract

“…Figure 7; Alexander et al 2003), which was found to be due to hot, optically thin silicate emission being extinguished by cool, optically thin silicate absorption. Such a combination of silicate emission and absorption is a common interpretation for the relatively flat spectra found in YSOs (Mitchell & Robinson 1981;Furlan et al 2008). Alternatively, the peaks at 9.2 and 11.3 μm may be due to crystalline silicates which are also commonly seen in YSOs (Olofsson et al 2009).…”

Section: Spitzer Irs Spectrummentioning

confidence: 88%

GAS AND DUST ABSORPTION IN THE DoAr 24E SYSTEM

Kruger

Richter

Seifahrt

et al. 2012

ApJ

View full text Add to dashboard Cite

We present findings for DoAr 24E, a binary system that includes a classical infrared companion. We observed the DoAr 24E system with the Spitzer Infrared Spectrograph (IRS), with high-resolution, near-infrared spectroscopy of CO vibrational transitions, and with mid-infrared imaging. The source of high extinction toward infrared companions has been an item of continuing interest. Here we investigate the disk structure of DoAr 24E using the column densities, temperature, and velocity profiles of two CO absorption features seen toward DoAr 24Eb. We model the SEDs found using T-ReCS imaging, and investigate the likely sources of extinction toward DoAr 24Eb. We find the lack of silicate absorption and small CO column density toward DoAr 24Eb suggest the mid-infrared continuum is not as extinguished as the near-infrared, possibly due to the mid-infrared originating from an extended region. This, along with the velocity profile of the CO absorption, suggests the source of high extinction is likely due to a disk or disk wind associated with DoAr 24Eb. Subject headings: circumstellar matter -protoplanetary disks -stars: pre-main-sequence -stars:individual (DoAr 24E)

show abstract

Discussion on “A Study on the Beginning of Secondary Compression of Soils” by R. G. Robinson

Cited by 5 publications

References 9 publications

SpitzerIRS Spectra and Envelope Models of Class I Protostars in Taurus

SpitzerIRS Spectra and Envelope Models of Class I Protostars in Taurus

The properties of 70 μm-selected high-redshift galaxies in the Extended Groth Strip

GAS AND DUST ABSORPTION IN THE DoAr 24E SYSTEM

Contact Info

Product

Resources

About