J/A+A/510/A27 Very low mass stars in Praesepe (Boudreault+, 2010)
Brown dwarfs and very low mass stars in the Praesepe open cluster:
a dynamically unevolved mass function?
Boudreault S., Bailer-Jones C.A.L., Goldman B., Henning T., Caballero J.A.
<Astron. Astrophys., 510, A27-27 (2010)>
=2010A&A...510A..27B 2010A&A...510A..27B
ADC_Keywords: Clusters, open ; Photometry, infrared
Keywords: open clusters and associations: individual: Praesepe -
stars: low-mass - stars: brown dwarfs -
stars: luminosity function, mass function - stars: formation
Abstract:
Determination of the mass functions of open clusters of different ages
allows us to infer the efficiency with which brown dwarfs are
evaporated from clusters to populate the field.
In this paper we present the results of a photometric survey to
identify low mass and brown dwarf members of the old open cluster
Praesepe (age 590+150-120Myr, distance 190+6.0-5.8pc) from
which we estimate its mass function and compare this with that of
other clusters.
We performed an optical (Ic-band) and near-infrared (J and Ks-band)
photometric survey of Praesepe covering 3.1°2. With 5sigma
detection limits of Ic=23.4 and J=20.0, our survey is predicted to be
sensitive to objects with masses from 0.6 to 0.05M_☉.
Description:
The near-infrared (NIR) observations were made on the 3.5m telescope
at Calar Alto, Spain (with observation runs of several nights from
February 2005 to January 2007).
The optical observations were carried out with the Wide Field Imager
(WFI) on the MPG/ESO 2.2m telescope at La Silla, Chile during 17-22
March 2007.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 65 151 All photometric cluster member candidates of
our survey
table4.dat 82 36 Photometric candidates in our survey that are
also photometric candidates in previous surveys
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See also:
J/A+AS/109/29 : Very low mass stars in Praesepe (Hambly+, 1995)
J/A+A/375/989 : JHK photometry of Praesepe low-mass stars (Bouvier+, 2001)
J/MNRAS/342/1241 : Low-mass stars in M45 and M44 (Pinfield+, 2003)
J/AJ/132/1517 : Spectroscopy of M dwarfs in Praesepe (Kafka+, 2006)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/927] Sequential number
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 15 F5.2 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 27 F4.1 arcsec DEs Declination (J2000)
29- 33 F5.2 mag Icmag Cousins I magnitude (1)
35- 39 F5.2 mag Jmag Johnson J magnitude (1)
41- 45 F5.2 mag Ksmag Johnson ks magnitude (1)
47- 51 F5.3 solMass Mass Derived mass
53- 56 I4 K Teff Effective temperature
58- 62 F5.2 mag JmagMod Model J magnitude (2)
64- 65 A2 --- SpT MK spectral type for BD candidates only (3)
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Note (1): The error on the determination of magnitude, effective
temperature and masses are:
* for stars (M>0.2solMass):
e_mag=0.002mag, e_Teff=140K and e_M=0.1solMass
* for very low-mass stars (0.072solMass<M<0.2solMass):
e_mag=0.01mag, e_Teff=230K and e_M=0.05solMass
* for BDs (M<0.072solMass)
e_mag=0.04mag, e_Teff=420K and e_M=0.02solMass
Note (2): The magnitude J is the predicted magnitude based on photometric
determination of Teff and Mass.
Note (3): Spectral type expected based on Teff and the temperature scale of
Kraus & Hillenbrand (2007, Cat. J/AJ/134/2340), with L1 set to 2100K.
The error on this estimation is one subclass.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/927] Sequential number, as in table3
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 15 F5.2 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 27 F4.1 arcsec DEs Declination (J2000)
29- 43 A15 --- 2MASSI Name from Adams et al. (2002,
Cat. J/AJ/124/1570) <JHHMMSSs+DDMMSS>
45- 61 A17 --- 2MASS Name from Kraus & Hillenbrand (2007,
Cat. J/AJ/134/2340) <JHHMMSSss+DDMMSSs>
63- 79 A17 --- 2MASSB Second Name from Kraus & Hillenbrand (2007,
Cat. J/AJ/134/2340) <JHHMMSSss+DDMMSSs>
81- 82 I2 --- PHJ ? Name from Pinfield et al.
(1997MNRAS.287..180P 1997MNRAS.287..180P)
<Cl* NGC 2632 PHJ NN> in Simbad
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History:
* 16-Jul-2010: table3 from electronic version of the journal
* 08-Feb-2011: Added table4
(End) Patricia Vannier [CDS] 16-Jul-2010