J/ApJ/796/127 Spitzer h and χ Persei candidate members (Cloutier+, 2014)
A deep Spitzer survey of circumstellar disks in the young double cluster,
h and χ Persei.
Cloutier R., Currie T., Rieke G.H., Kenyon S.J., Balog Z., Jayawardhana R.
<Astrophys. J., 796, 127 (2014)>
=2014ApJ...796..127C 2014ApJ...796..127C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stellar distribution ; Photometry, VRI ;
Photometry, infrared ; Equivalent widths
Keywords: circumstellar matter -
open clusters and associations: individual: NGC 869, NGC 884 -
planetary systems - protoplanetary disks - stars: formation
Abstract:
We analyze very deep Infrared Array Camera and Multiband Imaging
Photometer for Spitzer (MIPS) photometry of ∼12500 members of the 14 Myr
old Double Cluster, h and χ Persei, building upon our earlier,
shallower Spitzer Cycle 1 studies. Numerous likely members show
infrared (IR) excesses at 8 µm and 24 µm, indicative of
circumstellar dust. The frequency of stars with 8 µm excess is at
least 2% for our entire sample, slightly lower (higher) for B/A stars
(later type, lower mass stars). Optical spectroscopy also identifies
gas in about 2% of systems, but with no clear trend between the
presence of dust and gas. Spectral energy distribution modeling of 18
sources with detections at optical wavelengths through MIPS 24 µm
reveals a diverse set of disk evolutionary states, including a high
fraction of transitional disks, though similar data for all
disk-bearing members would provide constraints. Using Monte Carlo
simulations, we combine our results with those for other young
clusters to study the global evolution of dust/gas disks. For nominal
cluster ages, the e-folding times (τ0) for the frequency of warm
dust and gas are 2.75 Myr and 1.75 Myr, respectively. Assuming a
revised set of ages for some clusters, these timescales increase to
5.75 and 3.75 Myr, respectively, implying a significantly longer
typical protoplanetary disk lifetime than previously thought. In both
cases, the transitional disk duration, averaged over multiple
evolutionary pathways, is ∼1 Myr. Finally, 24 µm excess frequencies
for 4-6 M☉ stars appear lower than for 1-2.5 M☉ stars in
other 10-30 Myr old clusters.
Description:
The IRAC (Fazio et al. 2004ApJS..154...39F 2004ApJS..154...39F) observed h and χ Persei
on October 30, 2008 (AOR IDs 2182740, 21828608, 21828096, 21828864,
21828352, and 2182912). Solar activity was normal to below average.
Zodical emission ranged between ∼0.02 and 2 MJy/sr from 3.6 um to
8 um. Image processing and photometry were performed separately for
the short-exposure and long-exposure frames. The MIPS (Rieke et al.
2004ApJS..154...25R 2004ApJS..154...25R) imaged h and χ Persei on 2008 March 15-16,
2008 October 25-26, and 2009 March 26 and 29 as a part of General
Observation Programs 40690 and 50664 (PI: Scott Kenyon). To identify
and characterize disks surrounding h and χ Persei stars, we combine
Spitzer data with optical/near-IR data for likely cluster members,
updating the list from Currie et al. (2010, J/ApJS/186/191) with a more
accurate one of 13956 stars (Table 1).
Objects:
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RA (ICRS) DE Designation(s)
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02 20.5 +57 08 h and χ Persei = NAME NGC 869/884
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 13956 List of Candidate/Probable h and χ Persei
Members (Revised from Currie et al.
2010, J/ApJS/186/191)
table2.dat 200 12505 Photometry for Candidate/Probable
h and χ Persei Members
table4.dat 43 72 Candidate Accreting Stars
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See also:
V/27 : Proper Motions and UBV Photometry in h+chi Per (Muminov 1980)
J/AJ/122/248 : h and chi Per UBVI,Hα photometry (Keller+, 2001)
J/ApJ/576/880 : CCD UBV photometry of h and χ Per (Slesnick+, 2002)
J/PASP/114/233 : h and χ Per memberships (Uribe+, 2002)
J/ApJ/659/599 : IRAC and JHKs photometry of h and chi Persei (Currie+, 2007)
J/ApJ/669/L33 : Hα emission sources in h and χ Per (Currie+, 2007)
J/ApJ/672/558 : MIPS observations of h and χ Persei (Currie+, 2008)
J/ApJS/186/191 : VI photometry and spectroscopy in h+χ Per (Currie+, 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Member [1/13956] Member identification number
7- 11 I5 --- Phot Photometry running number (1)
13- 16 I4 --- Spec Spectroscopy running number (1)
18 I1 --- Type [1/3] Membership type (2)
20- 26 F7.4 deg RAdeg Right Ascension in decimal degrees (J2000)
28- 34 F7.4 deg DEdeg Declination in decimal degrees (J2000)
36- 43 F8.4 --- SpType Numerical spectral type (G1)
45- 51 F7.4 mag Vmag The V band magnitude (3)
53- 58 F6.4 mag e_Vmag The 1σ uncertainty in Vmag
60- 67 F8.4 mag Imag The I band magnitude (3)
69- 74 F6.4 mag e_Imag The 1σ uncertainty in Imag
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Note (1): A zero for either the photometry or spectroscopy running number means
that the source lacks either optical photometric or spectroscopic
data. The spectroscopy running number corresponds to the running
number from the combined photometry + spectroscopy table (Table 3),
not the running number from Table 2.
Note (2): Type as follows:
1 = Candidate member identified from photometry;
2 = Candidate member identified from spectroscopy;
3 = Candidate member identified from spectroscopy and photometry.
Note (3): The optical photometry listed here comes from that obtained in
Currie et al. (2010, J/ApJS/186/191), which may be saturated for the
brighest stars.
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Member [2/13956] Member identification number
7- 13 F7.4 deg RAdeg Right Ascension in decimal degrees (J2000)
15- 21 F7.4 deg DEdeg Declination in decimal degrees (J2000)
23- 30 F8.4 --- SpType Numerical spectral type (G1)
32- 38 F7.4 mag Vmag ?=-99.0 The V band magnitude (1)
40- 45 F6.4 mag e_Vmag ?=-99.0 The 1σ uncertainty in Vmag (1)
47- 54 F8.4 mag Imag ?=-99.0 The I band magnitude (1)
56- 61 F6.4 mag e_Imag ?=-99.0 The 1σ uncertainty in Imag (1)
63- 70 F8.4 mag Jmag ?=-99.0 2MASS J band magnitude (1)
72- 79 F8.4 mag e_Jmag ?=-99.0 The 1σ uncertainty in Jmag (1)
81- 88 F8.4 mag Hmag ?=-99.0 2MASS H band magnitude (1)
90- 97 F8.4 mag e_Hmag ?=-99.0 The 1σ uncertainty in Hmag (1)
99-106 F8.4 mag Kmag ?=-99.0 2MASS KS band magnitude (1)
108-115 F8.4 mag e_Kmag ?=-99.0 The 1σ uncertainty in Kmag (1)
117-124 F8.4 mag 3.6mag ?=-99.0 Spitzer/IRAC 3.6 micron band magnitude
(1)
126-132 F7.4 mag e_3.6mag ?=-99.0 The 1σ uncertainty in 3.6mag (1)
134-141 F8.4 mag 4.5mag ?=-99.0 Spitzer/IRAC 4.5 micron band magnitude
(1)
143-149 F7.4 mag e_4.5mag ?=-99.0 The 1σ uncertainty in 4.5mag (1)
151-158 F8.4 mag 5.8mag ?=-99.0 Spitzer/IRAC 5.8 micron band magnitude
(1)
160-166 F7.4 mag e_5.8mag ?=-99.0 The 1σ uncertainty in 5.8mag (1)
168-175 F8.4 mag 8mag ?=-99.0 Spitzer/IRAC 8 micron band magnitude (1)
177-183 F7.4 mag e_8mag ?=-99.0 The 1σ uncertainty in 8mag (1)
185-192 F8.4 mag 24mag ?=-99.0 Spitzer/MIPS 24 micron band magnitude (1)
194-200 F7.4 mag e_24mag ?=-99.0 The 1σ uncertainty in 24mag (1)
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Note (1): A -99.0000 indicates a null value.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.4 deg RAdeg Right Ascension in decimal degrees (J2000)
9- 15 F7.4 deg DEdeg Declination in decimal degrees (J2000)
17- 20 F4.1 --- SpType Numerical spectral type (G1)
22- 27 F6.2 0.1nm EWHa Equivalent width of Hα (Å)
29- 35 F7.3 mag [3.6]-[8] ?=-99.0 Spitzer/IRAC [3.6]-[8] color index
37- 43 F7.3 mag [4.5]-[8] ?=-99.0 Spitzer/IRAC [4.5]-[8] color index
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Global notes:
Note (G1): The numerical spectral type has the following formalism: 10=B0,
11=B1, ... , 68=M8.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 08-Aug-2017