J/ApJ/747/51 Lagoon Nebula stars. I. Rotation periods (Henderson+, 2012)
Time-series photometry of stars in and around the Lagoon Nebula.
I. Rotation periods of 290 low-mass pre-main-sequence stars in NGC 6530.
Henderson C.B., Stassun K.G.
<Astrophys. J., 747, 51 (2012)>
=2012ApJ...747...51H 2012ApJ...747...51H
ADC_Keywords: Stars, pre-main sequence ; Clusters, open ; Stars, masses ;
Cross identifications ; Photometry, VRI ; X-ray sources
Keywords: stars: individual: (NGC 6530) - stars: pre-main sequence -
stars: rotation
Abstract:
We have conducted a long-term, wide-field, high-cadence photometric
monitoring survey of ∼50000 stars in the Lagoon Nebula H II region.
This first paper presents rotation periods for 290 low-mass stars in
NGC 6530, the young cluster illuminating the nebula, and for which we
assemble a catalog of infrared and spectroscopic disk indicators,
estimated masses and ages, and X-ray luminosities. The distribution of
rotation periods we measure is broadly uniform for 0.5days<P<10days;
the short-period cutoff corresponds to breakup. We observe no obvious
bimodality in the period distribution, but we do find that stars with
disk signatures rotate more slowly on average. The stars' X-ray
luminosities are roughly flat with rotation period, at the saturation
level (log LX/Lbol~ -3.3). However, we find a significant
positive correlation between LX/Lbol and corotation radius,
suggesting that the observed X-ray luminosities are regulated by
centrifugal stripping of the stellar coronae. The period-mass
relationship in NGC 6530 is broadly similar to that of the Orion
Nebula Cluster (ONC), but the slope of the relationship among the
slowest rotators differs from that in the ONC and other young
clusters. We show that the slope of the period-mass relationship for
the slowest rotators can be used as a proxy for the age of a young
cluster, and we argue that NGC 6530 may be slightly younger than the
ONC, making it a particularly important touchstone for models of
angular momentum evolution in young, low-mass stars.
Description:
We have photometrically monitored the Lagoon Nebula over a period of
several years using the SMARTS 1.0m and 0.9m telescopes at the Cerro
Tololo Inter-American Observatory (CTIO). For this paper we use the
data from the longest of the observing runs, in 2006 June 15 to July
19 (35 nights) in Cousins I filter.
We also match each of the stars in our photometric database to the
Damiani et al. (2004, Cat. J/ApJ/608/781) X-ray source list using a
positional tolerance of 1.5" (see section 2).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 90 244 Parameters of the 244 cluster members with
definite rotation periods
table5.dat 90 46 Parameters of the 46 cluster members with
possible rotation periods
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See also:
J/A+A/548/A97 : Catalogue of variable stars in open clusters (Zejda+, 2012)
J/A+A/546/A9 : Stars spectral classification in NGC 6530 (Prisinzano+, 2012)
J/A+A/488/1221 : BMW-Chandra source catalog (Romano+, 2008)
J/A+A/462/123 : VLT/Flames spectroscopic data of NGC 6530 (Prisinzano+, 2007)
J/AJ/134/1368 : Proper motions in NGC 2244 and NGC 6530 (Chen+, 2007)
J/other/ChJAA/6.435 : Proper motions in NGC 6530 (Zhao+, 2006)
J/A+A/430/941 : Star formation region NGC 6530 (Prisinzano+, 2005)
J/ApJS/161/118 : byHα photometry in open clusters (McSwain+, 2005)
J/ApJ/608/781 : NGC 6530 Chandra X-ray catalog (Damiani+, 2004)
J/A+A/395/499 : XMM observations in M8 and NGC6530 (Rauw+, 2002)
J/AJ/120/333 : UBVRI and Hα in NGC 6530 (Sung+, 2000)
J/A+AS/123/63 : NGC 6530 multiwavelength photometry (van den Ancker+ 1997)
Byte-by-byte Description of file: table[45].dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- XID [2/875] X-ray identifier
(Cat. J/ApJ/608/781; <[DFM2004] NNN> in Simbad)
5- 9 I5 --- WFI [646/38914] WFI identifier (Cat. J/A+A/430/941;
<Cl* NGC 6530 WFI NNNNN> in Simbad)
11- 19 F9.5 deg RAdeg [270.94/271.25] Right Ascension (J2000)
21- 29 F9.5 deg DEdeg [-24.49/-24.20] Declination (J2000)
31- 36 F6.3 mag Vmag [14.52/21.83] The V band magnitude
38- 43 F6.3 mag Imag [13.27/18.05] The I band magnitude
45- 54 F10.7 d Per [0.1/19.1] Rotation period
56- 59 F4.2 Msun Mass [0.2/2.1] Mass
61- 65 F5.2 Myr Age [0.1/22.3] Age
67- 70 F4.2 Lsun Lbol [0.1/7.1] Bolometric luminosity
72- 75 F4.2 Rsun Rad [0.8/4.5] Radius
77- 82 F6.3 [10-7W] logLX [29/32] Log of X-ray luminosity; in erg/s
84 A1 --- IR? [Y/N/-] IR excess?
86 A1 --- Ha [C/W/-] Prisinzano et al. 2007 (J/A+A/462/123)
Hα TTau class (Classical or Weak-lined)
88 A1 --- r_Ha [b] b=Taken from Arias et al.
(2007MNRAS.374.1253A 2007MNRAS.374.1253A)
90 A1 --- SB2? [Y/N/-] Spectroscopic binary candidate?
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 25-Sep-2013