1999ApJ...525..772P


C.D.S. - SIMBAD4 rel 1.7 - 2020.10.21CEST16:09:19

1999ApJ...525..772P - Astrophys. J., 525, 772-783 (1999/November-2)

Star formation in the Orion nebula cluster.

PALLA F. and STAHLER S.W.

Abstract (from CDS):

We study the record of star formation activity within the dense cluster associated with the Orion Nebula. The bolometric luminosity function of 900 visible members is well matched by a simplified theoretical model for cluster formation. This model assumes that stars are produced at a constant rate and distributed according to the field-star initial mass function. Our best-fit age for the system, within this framework, is 2x106 yr. To undertake a more detailed analysis, we present a new set of theoretical pre-main-sequence tracks. These cover all masses from 0.1 to 6.0 M, and start from a realistic stellar birthline. The tracks end along a zero-age main-sequence that is in excellent agreement with the empirical one. As a further aid to cluster studies, we offer an heuristic procedure for the correction of pre-main-sequence luminosities and ages to account for the effects of unresolved binary companions. The Orion Nebula stars fall neatly between our birthline and zero-age main-sequence in the H-R diagram. All those more massive than about 8 M lie close to the main sequence, as also predicted by theory. After accounting for the finite sensitivity of the underlying observations, we confirm that the population between 0.4 and 6.0 M roughly follows a standard initial mass function. We see no evidence for a turnover at lower masses. We next use our tracks to compile stellar ages, also between 0.4 and 6.0 M. Our age histogram reveals that star formation began at a low level some 107 yr ago and has gradually accelerated to the present epoch. The period of most active formation is indeed confined to a fewx106 yr, and has recently ended with gas dispersal from the Trapezium. We argue that the acceleration in stellar births, which extends over a wide range in mass, reflects the gravitational contraction of the parent cloud spawning this cluster.

Abstract Copyright:

Journal keyword(s): Galaxy: Open Clusters and Associations: Individual: Name: Orion Nebula Cluster - Stars: Evolution - Stars: Formation - Stars: Pre-Main-Sequence

Simbad objects: 14

goto Full paper

goto View the reference in ADS

Number of rows : 14

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 IC 348 OpC 03 44 34 +32 09.8           ~ 1236 1
2 NAME Taurus Complex SFR 04 41.0 +25 52           ~ 3542 0
3 NAME Orion Nebula Cluster OpC 05 35.0 -05 29           ~ 2013 1
4 NAME Orion-KL SFR 05 35 14.16 -05 22 21.5           ~ 2025 1
5 NAME Trapezium Cluster As* 05 35 16.5 -05 23 14           ~ 1483 1
6 M 42 HII 05 35 17.3 -05 23 28           ~ 3751 0
7 NAME Ori A MoC 05 38 -07.1           ~ 2697 0
8 RMC 136 Cl* 05 38 42.396 -69 06 03.36           ~ 1751 1
9 V* YY Gem BY* 07 34 37.4475372002 +31 52 10.181030942 11.60 10.56 9.27 7.69 6.67 M0.5VeFe-2 820 0
10 NAME Chamaeleon Region SFR 11 55 -78.0           ~ 694 0
11 NAME Lup Cloud SFR 16 03 -38.1           ~ 531 0
12 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3063 0
13 V* CM Dra BY* 16 34 20.3299130309 +57 09 44.365524588   14.50 12.87 10.85 9.26 M4.5V 404 0
14 M 16 OpC 18 18 48 -13 48.4   6.58 6.0     ~ 944 2

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 1999ApJ...525..772P and select 'bookmark this link' or equivalent in the popup menu


2020.10.21-16:09:19

© Université de Strasbourg/CNRS

    • Contact