J/MNRAS/384/675 Monitoring low-mass stars in NGC 2362 (Irwin+ 2008)
The Monitor project: rotation of low-mass stars in NGC 2362 -
testing the disc regulation paradigm at 5 Myr.
Irwin J., Hodgkin S., Aigrain S., Bouvier J., Hebb L., Irwin M., Moraux E.
<Mon. Not. R. Astron. Soc., 384, 675-686 (2008)>
=2008MNRAS.384..675I 2008MNRAS.384..675I
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Photometry, infrared
Keywords: techniques: photometric - surveys - stars: pre-main-sequence -
stars: rotation - open clusters and associations: individual: NGC 2362
Abstract:
We report on the results of a time-series photometric survey of
NGC 2362, carried out using the CTIO 4-m Blanco telescope and
Mosaic-II detector as part of the Monitor project. Rotation periods
were derived for 271(*) candidate cluster members over the mass range
0.1~<M/M☉≲1.2. The rotation period distributions show a clear
mass-dependent morphology, qualitatively similar to that in NGC 2264,
as would be expected from the age of this cluster. Using models of
angular momentum evolution, we show that angular momentum losses over
the ∼1-5Myr age range appear to be needed in order to reproduce the
evolution of the slowest rotators in the sample from the ONC to
NGC 2362, as found by many previous studies. By incorporating Spitzer
IRAC mid-infrared (mid-IR) measurements, we found that three to four
objects showing mid-IR excesses indicative of the presence of
circumstellar discs were all slow rotators, as would be expected
in the disc regulation paradigm for early pre-main-sequence angular
momentum evolution, but this result is not statistically significant
at present, given the extremely limited sample size.
(*) The abstract indicates 271 clusters, but the actual number is 272.
Description:
Photometric monitoring observations were obtained using the 4-m CTIO
Blanco telescope, with the Mosaic-II imager, on 8x1/2-nights between
2005 December 24 and 2006 January 06.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 96 272 Properties of rotation candidates
--------------------------------------------------------------------------------
See also:
J/A+A/460/133 : Chandra X-ray sources in NGC 2362 (Damiani+, 2006)
J/AJ/130/1805 : Hα emission stars in NGC 2362 (Dahm+, 2005)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- [IHA2008b] Identifier, N2362-N-NNNNN (1)
15- 16 I2 h RAh Right ascension (J2000)
18- 19 I2 min RAm Right ascension (J2000)
21- 25 F5.2 s RAs Right ascension (J2000)
27 A1 --- DE- Declination sign (J2000)
28- 29 I2 deg DEd Declination (J2000)
31- 32 I2 arcmin DEm Declination (J2000)
34- 37 F4.1 arcsec DEs Declination (J2000)
39- 43 F5.2 mag Vmag V magnitude from CCD photometry
45- 49 F5.2 mag Imag I magnitude from CCD photometry
51- 55 F5.2 mag [3.6] ? Spitzer IRAC magnitude in 3.6um band
57- 61 F5.2 mag [4.5] ? Spitzer IRAC magnitude in 4.5um band
63- 67 F5.2 mag [5.8] ? Spitzer IRAC magnitude in 5.8um band
69- 73 F5.2 mag [8.0] ? Spitzer IRAC magnitude in 8.0um band
75- 80 F6.3 d Per Period
82- 86 F5.3 mag iamp Amplitude in i magnitude
(instrumental bandpass)
88- 91 F4.2 solMass Mass Interpolated mass (2)
93- 96 F4.2 solRad Rad Interpolated radius (2)
--------------------------------------------------------------------------------
Note (1): Our identifiers are formed using a simple scheme of the
cluster name, CCD number and a running count of stars in each
CCD, concatenated with dashes.
Note (2): from the models of Baraffe et al. 1998, Cat. J/A+A/337/403
derived using the I magnitudes.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 12-Jun-2008