J/A+A/570/A82 Mapping accretion variability in NGC 2264 (Venuti+, 2014)
Mapping accretion and its variability in the young open cluster NGC 2264:
a study based on u-band photometry.
Venuti L., Bouvier J., Flaccomio E., Alencar S.H.P., Irwin J.,
Stauffer J.R., Cody A.M., Teixeira P.S., Sousa A.P., Micela G.,
Cuillandre J.-C., Peres G.
<Astron. Astrophys. 570, A82 (2014)>
=2014A&A...570A..82V 2014A&A...570A..82V
ADC_Keywords: Clusters, open ; Accretion ; Photometry, CCD ; Photometry, SDSS
Keywords: accretion, accretion disks - stars: formation - stars: low-mass -
stars: pre-main sequence - ultraviolet: stars -
open clusters and associations: individual: NGC 2264
Abstract:
Our study aims at characterizing the accretion properties of several
hundred members of the star-forming region NGC 2264 (3Myr). We
performed a deep u,g,r,i mapping of the cluster with CFHT/MegaCam, and
monitored the simultaneous u+r variability of its members over a
baseline of two weeks. Stellar parameters are determined homogeneously
for about 750 monitored young objects, 40% of which are accreting T
Tauri stars. Accretion properties and accretion variability are
investigated and characterized from UV excess measurements.
Non-accreting members of the cluster define the reference UV emission
level over which flux excess is detected and measured.
Description:
We present homogeneous multi-band (optical+UV) photometry (table2) and
stellar parameters (table3: accreting/non-accreting status, spectral
type, Av, bolometric luminosity, stellar mass, stellar radius and age
estimate) for 757 young stars in the cluster (706 confirmed members +
51 newly identified candidates from our survey). In table4, we present
the UV excess measurements, u-band excess luminosity, median accretion
rates and their measured variability ranges for 237 accreting objects
in our sample.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 57 757 Photometry for NGC 2264 members monitored at CFHT
table3.dat 51 757 Spectral type, extinction and stellar parameters
for NGC 2264 members monitored at CFHT
table4.dat 54 237 UV excess, u-band excess luminosity, accretion
rate and accretion rate variability estimates
for NGC 2264 accreting members
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See also:
J/AJ/114/2644 : UBVRIHa photometry of NGC2264 (Sung+, 1997)
J/A+A/345/521 : BVRI photometry of NGC 2264 (Flaccomio+, 1999)
J/A+A/355/651 : HRI observations of PMS stars in NGC 2264 (Flaccomio+, 2000)
J/AJ/123/1528 : UBV(RI)C and JHK photometry in NGC 2264 (Rebull+, 2002)
J/A+A/417/557 : Rotation + variability of PMS Stars in NGC 2264 (Lamm, 2004)
J/A+A/430/1005 : VRIHα photometry of NGC 2264 variables (Lamm+, 2005)
J/A+A/455/903 : ACIS-I observations of NGC 2264 (Flaccomio+, 2006)
J/AJ/127/1117 : Halpha emission-line stars in NGC2264 (Reipurth+, 2004)
J/AJ/127/2228 : VRI photometry of PMS stars in NGC 2264 OB (Makidon+, 2004)
J/AJ/127/2659 : CHANDRA observations of NGC 2264 (Ramirez+, 2004)
J/AJ/128/1684 : NGC 2264: VRIHα photometry (Sung+, 2004)
J/AJ/129/829 : Hα emission stars in NGC 2264 (Dahm+, 2005)
J/ApJ/648/1090 : Radial velocities of NGC 2264 stars (Furesz+, 2006)
J/ApJ/671/605 : NGC 2264 and ONC PMS stars in the infrared (Cieza+, 2007)
J/AJ/134/999 : X-ray observations of NGC 2264 (Dahm+, 2007)
J/AJ/135/441 : VRIHα photometry in NGC 2264 (Sung+, 2008)
J/AJ/138/963 : Rotation of NGC 2264 members (Baxter+, 2009)
J/AJ/138/1116 : A Spitzer view of NGC 2264 (Sung+, 2009)
J/ApJ/741/35 : NIR photometry and polarization in NGC 2264 (Kwon+, 2011)
J/MNRAS/430/1433 : NGC 2264 members periods with CoRoT (Affer+, 2013)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [Mon-]
5- 10 I06 --- Mon Object identifier (G1)
12- 20 F9.5 deg RAdeg Right ascension (J2000)
22- 29 F8.5 deg DEdeg Declination (J2000)
31- 36 F6.3 mag umag u-band apparent magnitude
38- 43 F6.3 mag gmag ?=- g-band apparent magnitude
45- 50 F6.3 mag rmag r-band apparent magnitude
52- 57 F6.3 mag imag ?=- i-band apparent magnitude
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [Mon-]
5- 10 I06 --- Mon Object identifier (G1)
12- 13 A2 --- St CTTS (accreting) vs. WTTS (non-accreting)
classification for members (1)
15- 21 A7 --- SpT Spectral type of the object
23 A1 --- r_SpT [sp] spectroscopic or photometric type (2)
25- 27 F3.1 mag Av [0/7.1]?=- Visual extinction
29- 35 F7.4 Lsun Lbol Bolometric luminosity of the object
37- 40 F4.2 Msun Mass ?=- Stellar mass
42- 46 F5.2 Rsun Rad ?=- Stellar radius
48- 51 F4.2 [yr] logAge ?=- Logarithm of the age of the object
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Note (1): Classification code as follows:
c = CTTS (classical T Tau star)
w = WTTS (weak-line T Tau star)
cc = CTTS candidate.
c* = the object is a member that was previously classified as WTTS and
is re-classified as CTTS in this study
Note (2): spectral type estimate from:
s = spectroscopic SpType estimate (retrieved from literature)
p = photometric SpType estimate (from CFHT optical colors)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [Mon-]
5- 10 I06 --- Mon Object identifier (G1)
12- 16 F5.2 mag E(u-g) UV excess measured from the u-g color index
18- 22 F5.2 mag E(u-r) ?=- UV excess measured from the u-r
color index (1)
24- 28 F5.2 [Lsun] logLEu ?=- Logarithm of the measured u-band excess
luminosity (1)
30- 35 F6.2 [Msun/yr] logMa.g ?=- Log of the mass accretion rate derived
from the (u-g) color excess
36 A1 --- l_logMa.g [*] indicates an upper limit at the detection
threshold (see text)
38- 43 F6.2 [Msun/yr] logMa.r ?=- Log of the mass accretion rate derived
from the (u-r) color excess (1)
44 A1 --- l_logMa.r [*] * indicates an upper limit at the detection
threshold (see text)
46- 49 F4.2 [Msun/yr] var+ ?=- Positive (u-r) accretion variability bar
log(max/med) (2)
51- 54 F4.2 [Msun/yr] var- ?=- Negative (u-r) accretion variability bar
log(med/min) (2)
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Note (1): Value measured at the median luminosity state of the system.
Note (2): Variability range (from maximum to minimum value measured) detected
around the median mass accretion rate level during the 2 week-long u,r
monitoring. If no accretion activity is detected above the detection limit
for the object at the minimum/median luminosity level, but some significant
accretion is detected at the brightest state, only the upper variability bar
is reported; if the object is a non-detection in accretion, no variability
measurement is reported.
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Global notes:
Note (G1): Object identifiers adopted within the CSI 2264 project
(see Cody et al., 2014AJ....147...82C 2014AJ....147...82C), Mon-NNNNNN.
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Acknowledgements:
Laura Venuti, Laura.Venuti(at)obs.ujf-grenoble.fr
(End) Laura Venuti [IPAG, France], Patricia Vannier [CDS] 07-Aug-2014