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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy

2009

Dartmouth College

Mass

Articles 1 - 4 of 4

Full-Text Articles in Physical Sciences and Mathematics

Dust And The Type Ii-Plateau Supernova 2004et, R. Kotak, W. P. S. Meikle, D. Farrah, C. L. Gerardy, R. J. Foley, S. D. Van Dyk, C. Fransson, P. Lundqvist, J. Sollerman, R. Fesen Oct 2009

Dust And The Type Ii-Plateau Supernova 2004et, R. Kotak, W. P. S. Meikle, D. Farrah, C. L. Gerardy, R. J. Foley, S. D. Van Dyk, C. Fransson, P. Lundqvist, J. Sollerman, R. Fesen

Dartmouth Scholarship

We present mid-infrared (MIR) observations of the Type II-plateau supernova (SN) 2004et, obtained with the Spitzer Space Telescope between 64 and 1406 days past explosion. Late-time optical spectra are also presented. For the period 300-795 days past explosion, we argue that the spectral energy distribution (SED) of SN 2004et comprises (1) a hot component due to emission from optically thick gas, as well as free-bound radiation; (2) a warm component due to newly formed, radioactively heated dust in the ejecta; and (3) a cold component due to an IR echo from the interstellar-medium dust of the host galaxy, NGC 6946. …


Sdss J102347.6+003841: A Millisecond Radio Pulsar Binary That Had A Hot Disk During 2000-2001, Zhongxiang Wang, Anne M. Archibald, John R. Thorstensen, Victoria M. Kaspi Oct 2009

Sdss J102347.6+003841: A Millisecond Radio Pulsar Binary That Had A Hot Disk During 2000-2001, Zhongxiang Wang, Anne M. Archibald, John R. Thorstensen, Victoria M. Kaspi

Dartmouth Scholarship

The Sloan Digital Sky Survey (SDSS) source J102347.6+003841 was recently revealed to be a binary 1.69 ms radio pulsar with a 4.75 hr orbital period and a ~0.2 M companion. Here, we analyze the SDSS spectrum of the source in detail. The spectrum was taken on 2001 February 1, when the source was in a bright state and showed broad, double-peaked hydrogen and helium lines—dramatically different from the G-type absorption spectrum seen from 2002 May onward. The lines are consistent with emission from a disk around the compact primary. We derive properties of the disk by fitting the SDSS …


Subaru High-Resolution Spectroscopy Of Star G In The Tycho Supernova Remnant, Wolfgang E. Kerzendorf, Brian P. Schmidt, M. Asplund, Ken'ichi Nomoto, Ph. Podsiadlowski, Anna Frebel, Robert A. Fesen, David Yong Aug 2009

Subaru High-Resolution Spectroscopy Of Star G In The Tycho Supernova Remnant, Wolfgang E. Kerzendorf, Brian P. Schmidt, M. Asplund, Ken'ichi Nomoto, Ph. Podsiadlowski, Anna Frebel, Robert A. Fesen, David Yong

Dartmouth Scholarship

It is widely believed that Type Ia supernovae (SNe Ia) originate in binary systems where a white dwarf accretes material from a companion star until its mass approaches the Chandrasekhar mass and carbon is ignited in the white dwarf's core. This scenario predicts that the donor star should survive the supernova (SNe) explosion, providing an opportunity to understand the progenitors of SNe Ia. In this paper, we argue that rotation is a generic signature expected of most nongiant donor stars that is easily measurable. Ruiz-Lapuente et al. examined stars in the center of the remnant of SN 1572 (Tycho SN) …


New Neighbors: Parallaxes Of 18 Nearby Stars Selected From The Lspm-North Catalog, Sébastien Lépine, John R. Thorstensen, Michael M. Shara, R. Michael Rich Mar 2009

New Neighbors: Parallaxes Of 18 Nearby Stars Selected From The Lspm-North Catalog, Sébastien Lépine, John R. Thorstensen, Michael M. Shara, R. Michael Rich

Dartmouth Scholarship

We present astrometric parallaxes for 18 suspected nearby stars selected from the LSPM-north proper motion catalog. 16 objects are confirmed to be main-sequence M dwarfs within 16 pc of the Sun, including three stars (LSPM J0011+5908, LSPM J0330+5413, and LSPM J0510+2714) which lie just within the 10 pc horizon. Two other targets (LSPM J1817+1328, LSPM J2325+1403) are confirmed to be nearby white dwarfs at distances of 14 and 22 pc, respectively. One of our targets, the common proper motion pair LSPM J0405+7116E + LSPM J0405+7116W, is revealed to be a triple system, with the western component resolved into a pair …