J/MNRAS/435/2474 USco ZYJHK1K2 photometry and proper motions (Lodieu+, 2013)
Probing the Upper Scorpius mass function in the planetary-mass regime.
Lodieu N., Dobbie P.D., Cross N.J.G., Hambly N.C., Read M.A., Blake R.P.,
Floyd D.J.E.
<Mon. Not. R. Astron. Soc., 435, 2474-2482 (2013)>
=2013MNRAS.435.2474L 2013MNRAS.435.2474L
ADC_Keywords: Associations, stellar ; Photometry, infrared ; Proper motions
Keywords: techniques: photometric - surveys - brown dwarfs - stars: low-mass -
stars: luminosity function, mass function - infrared: stars
Abstract:
We present the results of a deep ZYJ near-infrared survey of
13.5deg2 in the Upper Scorpius (USco) OB association. We
photometrically selected ∼100 cluster member candidates with masses in
the range of 30-5 Jupiters, according to state-of-the-art evolutionary
models. We identified 67 ZYJ candidates as bona fide members, based on
complementary photometry and astrometry. We also extracted five
candidates detected with Visible and Infrared Survey Telescope for
Astronomy at YJ only. One is excluded using deep optical z-band
imaging, while two are likely non-members, and three remain as
potential members. We conclude that the USco mass function is more
likely decreasing in the planetary-mass regime (although a flat mass
function cannot yet be discarded), consistent with surveys in other
regions.
Description:
We performed a near-infrared survey of 13.5deg2 in USco with the
VISTA InfraRed CAMera (VIRCAM) mounted on VISTA telescope in Paranal,
Chile. We imaged USco in the ZYJ filters in service mode between 2012
April and May.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 129 67 USco member candidates in the VISTA deep survey
table3.dat 129 43 USco candidates classified as photometric
and/or astrometric non-members
table4.dat 64 5 Z-band dropouts (or YJ-only) candidates in USco
--------------------------------------------------------------------------------
See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
J/AJ/120/479 : Low-mass stars in the Upper Sco association (Ardila+, 2000)
J/ApJ/651/L49 : Upper Sco OB association IRAC observations (Carpenter+ 2006)
J/ApJ/705/1646 : Debris disks in Upper Sco (Carpenter+, 2009)
J/A+A/527/A24 : Spectra of low-mass stars in Upper Sco (Lodieu+, 2011)
J/ApJ/745/56 : Upper Sco members rotational velocities (Dahm+, 2012)
J/ApJ/758/31 : IR photometry for members of Upper Sco (Luhman+, 2012)
J/MNRAS/373/95 : ZYJHK survey of Upper Sco association (Lodieu+, 2006)
J/MNRAS/374/372 : ZYJHK photometry in Upper Sco (Lodieu+, 2007)
J/MNRAS/418/1231 : New brown dwarfs in upper Sco (Dawson+, 2011)
J/MNRAS/431/3222 : UKIDSS GCS Upper Sco members (Lodieu, 2013)
Byte-by-byte Description of file: table2.dat table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Right ascension (J2000)
4- 5 I2 min RAm Right ascension (J2000)
7- 11 F5.2 s RAs Right ascension (J2000)
13 A1 --- DE- Declination sign (J2000)
14- 15 I2 deg DEd Declination (J2000)
17- 18 I2 arcmin DEm Declination (J2000)
20- 23 F4.1 arcsec DEs Declination (J2000)
25- 30 F6.3 mag Zmag ?=- VISTA Z magnitude
32- 36 F5.3 mag e_Zmag ?=- rms uncertainty on Zmag
38- 43 F6.3 mag Ymag VISTA Y magnitude
45- 49 F5.3 mag e_Ymag rms uncertainty on Ymag
51- 56 F6.3 mag Jmag VISTA J magnitude
58- 62 F5.3 mag e_Jmag rms uncertainty on Jmag
64- 69 F6.3 mag Hmag ?=- UKIDSS H magnitude
71- 75 F5.3 mag e_Hmag ?=- rms uncertainty on Hmag
77- 82 F6.3 mag K1mag ?=- UKIDSS K1 magnitude
84- 88 F5.3 mag e_K1mag ?=- rms uncertainty on K1mag
90- 95 F6.3 mag K2mag ?=- UKIDSS K2 magnitude
97-101 F5.3 mag e_K2mag ?=- rms uncertainty on K2mag
103-109 F7.2 mas/yr pmRA ?=- Proper motion along RA
111-115 F5.2 mas/yr e_pmRA ?=- rms uncertainty on pmRA
117-123 F7.2 mas/yr pmDE ?=- Proper motion along DE
125-129 F5.2 mas/yr e_pmDE ?=- rms uncertainty on pmDE
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Right ascension (J2000)
4- 5 I2 min RAm Right ascension (J2000)
7- 11 F5.2 s RAs Right ascension (J2000)
13 A1 --- DE- Declination sign (J2000)
14- 15 I2 deg DEd Declination (J2000)
17- 18 I2 arcmin DEm Declination (J2000)
20- 23 F4.1 arcsec DEs Declination (J2000)
25- 30 F6.3 mag Ymag VISTA Y magnitude
32- 36 F5.3 mag e_Ymag rms uncertainty on Ymag
38- 43 F6.3 mag Jmag VISTA J magnitude
45- 49 F5.3 mag e_Jmag rms uncertainty on Jmag
51 A1 --- l_Kmag Limit flag on Kmag
52- 57 F6.3 mag Kmag ?=- UKIDSS K magnitude (GCS DR10)
59- 63 F5.3 mag e_Kmag ?=- rms uncertainty on K1mag
64 A1 --- n_Kmag [abc] Note on Kmag (1)
--------------------------------------------------------------------------------
Note (1): Notes as follows:
a = We list the K-band magnitude with the lowest error bar: the other
measurement available from GCS DR10 gives K=17.579±0.133mag.
b = This object, covered by our IMACS survey, has a magnitude of
21.878 (Z-J=20.8mag) and is rejected as a member.
c = This candidate lies in the vignetted part of the IMACS detector.
We estimated its Z-J colour to 2.14-2.79mag.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 09-Oct-2014