國立高雄大學圖資館 |

登入

回首頁

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:	Adviser: Scott J. Kenyon.
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 [electronic resource] - 140 p.

Adviser: Scott J. Kenyon.

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

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.

ISBN: 049679034XSubjects--Topical Terms:

227131
Physics, Astronomy and Astrophysics.

The structure and initial mass function of h and chi Persei
LDR:03052nmm _2200301 _450 001 162675
005 20051017073511.5
008 230606s2004 eng d
020 $a 049679034X
035 $a 00149176
035 $a 162675
040 $a UnM $c UnM
100 0 $a Bragg, Ann Elizabeth. $3 227819
245 1 4 $a The structure and initial mass function of h and chi Persei $h [electronic resource]
300 $a 140 p.
500 $a Adviser: Scott J. Kenyon.
500 $a Source: Dissertation Abstracts International, Volume: 65-05, Section: B, page: 2450.
502 $a Thesis (Ph.D.)--Harvard University, 2004.
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.
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 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.
590 $a School code: 0084.
650 # 0 $a Physics, Astronomy and Astrophysics. $3 227131
690 $a 0606
710 0 # $a Harvard University. $3 212445
773 0 # $g 65-05B. $t Dissertation Abstracts International
790 $a 0084
790 1 0 $a Kenyon, Scott J., $e advisor
791 $a Ph.D.
792 $a 2004
856 4 0 $u http://libsw.nuk.edu.tw/login?url=http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3131794 $z http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3131794