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相关论文: A polycrystalline graphite model for the 2175 Angs…

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A new 3.2--3.5~$\mu$m spectrum of the protostar Mon~R2/IRS-3 confirms our previous tentative detection of a new absorption feature near 3.25 $\mu$m. The feature in our new spectrum has a central wavelength of 3.256 $\mu$m (3071 cm$^{-1}$)…

天体物理学 · 物理学 2009-10-28 K. Sellgren , T. Y. Brooke , R. G. Smith

We have analyzed the 9.7 and ``18'' micron interstellar silicate absorption features along the line of sight toward four heavily extincted galactic WC-type Wolf-Rayet (WR) stars. We construct two interstellar extinction curves from 1.25 to…

天体物理学 · 物理学 2009-11-13 J. E. Chiar , A. G. G. M. Tielens

The dust extinction curve is typically parameterized by a single variable, R(V), in optical and near-infrared wavelengths. R(V) controls the slope of the extinction-vs.-wavelength curve, and is thought to reflect the grain-size distribution…

星系天体物理 · 物理学 2025-06-26 Gregory M. Green , Xiangyu Zhang , Ruoyi Zhang

Particle shape and aggregation have a strong influence on the spectral profiles of infrared phonon bands of solid dust grains. Calculating these effects is difficult due to the often extreme refractive index values in these bands. In this…

天体物理学 · 物理学 2007-05-23 Anja C. Andersen , Harald Mutschke , Thomas Posch , Michiel Min , Akemi Tamanai

In pyrocarbon materials, the width of the Raman D band (FWHMD) is very sensitive to low energy structural defects (e.g., disorientations of the graphene layers). The correlation between the two parameters, FWHMD and OA (as derived from…

地球物理 · 物理学 2007-07-03 Jean-Marie Vallerot , Xavier Bourrat , Arnaud Mouchon , Georges Chollon

We report the clear detection of the 2175A dust absorption feature in the optical afterglow spectrum of the gamma-ray burst (GRB) GRB070802 at a redshift of z=2.45. This is the highest redshift for a detected 2175A dust bump to date, and it…

We find experimentally that the optical sheet conductance of graphite per graphene layer is very close to $(\pi/2)e^2/h$, which is the theoretically expected value of dynamical conductance of isolated monolayer graphene. Our calculations…

强关联电子 · 物理学 2009-11-13 A. B. Kuzmenko , E. van Heumen , F. Carbone , D. van der Marel

We present a new determination of the dust content and near-ultraviolet/optical extinction curves associated with a sample of ~8300 strong (equivalent width > 1A) Mg II absorbers, with redshifts 0.4<z<2.2, identified in Sloan Digital Sky…

宇宙学与河外天体物理 · 物理学 2015-05-28 J. M. Budzynski , P. C. Hewett

We use FUSE and STIS spectra to study intergalactic absorption towards the quasar PG1259+593 (z=0.478). We identify 135 intergalactic absorption lines with equivalent widths >10mA, tracing 78 absorption components in 72 Ly alpha/beta…

天体物理学 · 物理学 2009-11-10 Philipp Richter , Blair D. Savage , Todd M. Tripp , Kenneth R. Sembach

We combine near-infrared (2MASS) and mid-infrared (Spitzer-IRAC) photometry to characterize the IR extinction law (1.2-8 microns) over nearly 150 degrees of contiguous Milky Way midplane longitude. The relative extinctions in 5 passbands…

This work purports to help understand the InterStellar Extinction Curve in and near the visible range. In this range, crystalline materials are known to be transparent, so amorphous dust is needed. Molecular modeling experiments are used to…

星系天体物理 · 物理学 2019-05-21 Renaud Papoular

We use more than 872,000 mid-to-high resolution (R $\sim$ 20,000) spectra of stars from the GALAH survey to discern the spectra of diffuse interstellar bands (DIBs). We use four windows with the wavelength range from 4718 to 4903, 5649 to…

The 2175 {\AA} bump shows considerable variations in its strength, width, and central wavelength when observed along different sightlines in the Milky Way and other galaxies. These variations offer valuable insights into the composition,…

天体物理仪器与方法 · 物理学 2024-07-23 Joice Mathew , Andrew Battisti , Israel Vaughn , Shubhangi Jain , Rekhesh Mohan , Jayant Murthy

We present a sample of low-resolution 5-38um Spitzer IRS spectra of the inner few square kiloparsecs of 59 nearby galaxies spanning a large range of star formation properties. A robust method for decomposing mid-infrared galaxy spectra is…

Depletion studies provide a way to understand the chemical composition of interstellar dust grains. We here examine 23 gamma-ray bursts (GRB) optical afterglow spectra (spanning 0.6<z<5.0) and compare their silicon and iron dust-phase…

星系天体物理 · 物理学 2019-10-16 T. Zafar , K. E. Heintz , A. Karakas , J. Lattanzio , A. Ahmad , Macquarie Uni , Austalia , Uni. Iceland , Iceland , Monash Uni , Australia

Based on the data obtained from the Spitzer/GLIPMSE Legacy Program and the 2MASS project, we derive the extinction in the four IRAC bands, [3.6], [4.5], [5.8] and [8.0] micron, relative to the 2MASS Ks band (at 2.16 micron) for 131 GLIPMSE…

星系天体物理 · 物理学 2014-11-20 Jian Gao , B. W. Jiang , A. Li

We present a moderate-resolution (~20 km/s) spectrum of the mini broad-absorption-line QSO PG1351+64 between 915-1180 A, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional spectra at longer wavelengths were also…

We construct extinction curves based on Mie's theory for spherical dust grain with size distributions between 50-2500 A and composed by elements found in meteorites. We explore the issue of whether the observed spectral energy distribution…

天体物理学 · 物理学 2008-02-21 Sinhue Amos Refugio Haro-Corzo , Luc Binette

We used 3D maps of 862nm DIB equivalent width (EW) and extinction, DIB catalogues, and measured parameters of dust extinction law and dust emission to study relationships between DIB and extinction level, total-to-selective extinction ratio…

星系天体物理 · 物理学 2024-10-30 R. Lallement , J. L. Vergely , N. L. J. Cox

The annihilation of positrons in the Galaxy's interstellar medium produces characteristic gamma-rays with a line at 511 keV. This emission has been observed with the spectrometer SPI on INTEGRAL, confirming a puzzling morphology with bright…