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The structure and initial mass funct...

Bragg, Ann Elizabeth.

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The structure and initial mass function of h and chi Persei.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	The structure and initial mass function of h and chi Persei./
作者:	Bragg, Ann Elizabeth.
面頁冊數:	140 p.
附註:	Source: Dissertation Abstracts International, Volume: 65-05, Section: B, page: 2450.
Contained By:	Dissertation Abstracts International65-05B.
標題:	Physics, Astronomy and Astrophysics. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3131794
ISBN:	049679034X

The structure and initial mass function of h and chi Persei.
Bragg, Ann Elizabeth.

The structure and initial mass function of h and chi Persei. - 140 p.

Source: Dissertation Abstracts International, Volume: 65-05, Section: B, page: 2450.

Thesis (Ph.D.)--Harvard University, 2004.

We study h and chi Persei, a pair of young open clusters, using optical (UBV) and infrared (JHK) photometry, plus optical spectra of over 1600 stars. Our spectroscopic survey is complete to V = 15.2 within 12.5' of the cluster centers. Using an automated type-assignment routine, we derive spectral types from the spectra. The accuracy of this method is comparable to that obtained by visual typing.

ISBN: 049679034XSubjects--Topical Terms:

1019521
Physics, Astronomy and Astrophysics.

The structure and initial mass function of h and chi Persei.
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245 1 4 $a The structure and initial mass function of h and chi Persei.
300 $a 140 p.
500 $a Source: Dissertation Abstracts International, Volume: 65-05, Section: B, page: 2450.
500 $a Adviser: Scott J. Kenyon.
502 $a Thesis (Ph.D.)--Harvard University, 2004.
520 $a We study h and chi Persei, a pair of young open clusters, using optical (UBV) and infrared (JHK) photometry, plus optical spectra of over 1600 stars. Our spectroscopic survey is complete to V = 15.2 within 12.5' of the cluster centers. Using an automated type-assignment routine, we derive spectral types from the spectra. The accuracy of this method is comparable to that obtained by visual typing.
520 $a We identify 32 Be stars in our spectroscopic sample; some have low Halpha emission strength. Seven of these are new identifications; seven others are confirmations of Be stars previously identified using photometry. Five of the observed Be stars show significant Halpha profile variations from epoch to epoch. We show that spectral indices yield physical characteristics of the HII emission region. We infer Halpha:Hbeta flux ratios of 2--5 and observe a linear relationship between Halpha emission and J-K color.
520 $a We measure an extinction to the clusters of AV = 1.66 mag. We measure cluster centers alpha(2000) = 2h 18m 56.4s +/- 3.0s, delta(2000) = 57°8' 25" +/- 23" and alpha(2000) = 2h 22m 4.3s +/- 2.9s, delta(2000) = 57°8' 35" +/- 25", for h and chi Persei, respectively. We fit a modified Hubble law to the stellar positions and measure core radii of 1.9 pc and 2.4 pc. Integration of the Miller-Scalo IMF suggests cluster masses of 5500 M&odot; and 4300 M&odot; and central densities of 27 M&odot; pc-3 and 50 M&odot; pc-3. We find mass segregation in h Persei, but not in chi Persei. Examination of the dynamical timescales suggests that the mass segregation must be in part primordial.
520 $a We determine the cluster ages, log t = 7.05 and log t = 7.1, for h + chi Persei using M supergiants. Using the HR Diagram, we measure IMF slopes of -2.47 +/- 0.12 and -2.30 +/- 0.15 for h and chi Persei. These slopes are consistent with the Salpeter IMF. The slope in h Persei is shallower towards the cluster center, consistent with mass segregation. Mysteriously, while h Persei is younger, it is also more dynamically evolved.
590 $a School code: 0084.
650 4 $a Physics, Astronomy and Astrophysics. $3 1019521
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710 2 0 $a Harvard University. $3 528741
773 0 $t Dissertation Abstracts International $g 65-05B.
790 1 0 $a Kenyon, Scott J., $e advisor
790 $a 0084
791 $a Ph.D.
792 $a 2004
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3131794