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Physical Sciences and Mathematics Commons

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Astrophysics and Astronomy

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Dartmouth College

2010

Morphology

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

On Using The Color-Magnitude Diagram Morphology Of M67 To Test Solar Abundances, Z. Magic, A. Serenelli, A. Weiss, B. Chaboyer Aug 2010

On Using The Color-Magnitude Diagram Morphology Of M67 To Test Solar Abundances, Z. Magic, A. Serenelli, A. Weiss, B. Chaboyer

Dartmouth Scholarship

The open cluster M67 has solar metallicity and an age of about 4 Gyr. The turnoff (TO) mass is close to the minimum mass for which solar metallicity stars develop a convective core during main sequence evolution as a result of the development of hydrogen burning through the CNO cycle. The morphology of the color-magnitude diagram (CMD) of M67 around the TO shows a clear hook-like feature, a direct sign that stars close to the TO have convective cores. VandenBerg et al. investigated the possibility of using the morphology of the M67 TO to put constraints on the solar metallicity, …


The Nature Of The Strong 24 Μmspitzersource J222557+601148: Not A Young Galactic Supernova Remnant, Robert A. Fesen, Dan Milisavljevic May 2010

The Nature Of The Strong 24 Μmspitzersource J222557+601148: Not A Young Galactic Supernova Remnant, Robert A. Fesen, Dan Milisavljevic

Dartmouth Scholarship

The nebula J222557+601148, tentatively identified by Morris et al. as a young Galactic supernova remnant (SNR) from Spitzer Galactic First Look Survey images and a follow-up mid-infrared spectrum, is unlikely to be an SNR remnant based on Hα, [O III], [S II] images, and low-dispersion optical spectra. The object is seen in Hα and [O III] λ5007 images as a faint, roughly circular ring nebula with dimensions matching that seen in 24 μm Spitzer images. Low-dispersion optical spectra show it to have narrow Hα and [N II] λλ6548,6583 line emissions with no evidence of broad or high-velocity (v ≥ …


Core Gas Sloshing In Abell 1644, Ryan E. Johnson, Maxim Markevitch, Gary A. Wegner, Christine Jones, William R. Forman Feb 2010

Core Gas Sloshing In Abell 1644, Ryan E. Johnson, Maxim Markevitch, Gary A. Wegner, Christine Jones, William R. Forman

Dartmouth Scholarship

We present an analysis of a 72 ks Chandra observation of the double cluster Abell 1644 (z = 0.047). The X-ray temperatures indicate that the masses are M 500 = (2.6 ± 0.4) × 1014 h –1 M for the northern sub-cluster and M 500 = (3.1 ± 0.4) × 1014 h –1 M for the southern, main cluster. We identify a sharp edge in the radial X-ray surface brightness of the main cluster, which we find to be a cold front, with a jump in temperature of a factor of ~3. This edge possesses …