J/ApJ/688/597 Debris disks in NGC 2232 (Currie+, 2008)
A Spitzer study of debris disks in the young nearby cluster NGC 2232: icy
planets are common around ∼1.5-3 M☉ stars.
Currie T., Plavchan P., Kenyon S.J.
<Astrophys. J., 688, 597-615 (2008)>
=2008ApJ...688..597C 2008ApJ...688..597C
ADC_Keywords: Clusters, open ; Photometry, infrared ; Stars, dwarfs ;
Spectral types ; Equivalent widths ; Spectroscopy
Keywords: circumstellar matter - open clusters and associations: individual
(NGC 2232) - planetary systems: formation - planetary systems:
protoplanetary disks - stars: pre-main sequence
Abstract:
We describe Spitzer IRAC and MIPS observations of the nearby 25Myr old
open cluster NGC 2232. Combining these data with ROSAT All-Sky Survey
observations, proper motions, and optical photometry/spectroscopy, we
construct a list of highly probable cluster members. We identify one
A-type star, HD 45435, that has definite excess emission at 4.5-24um
indicative of debris from terrestrial planet formation. We also
identify 2-4 late-type stars with possible 8um excesses and 8
early-type stars with definite 24um excesses. Constraints on the dust
luminosity and temperature suggest that the detected excesses are
produced by debris disks. From our sample of B and A stars, stellar
rotation appears to be correlated with 24um excess, a result that
would be expected if massive primordial disks evolve into massive
debris disks. To explore the evolution of the frequency and magnitude
of debris around A-type stars, we combine our results with data for
other young clusters.
Description:
Observations of NGC 2232 were taken with the Infrared Array Camera
(IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS) on
2005 March 29 and 2005 April 4 as a part of the Guaranteed Time
Observations program (Program ID 37). To supplement the Spitzer
data, we queried the High Energy Astrophysics Science Archive
Research Center database (HEASARC) for ROSAT detections from the
High-Resolution Imager (HRI) that were within 2° of NGC 2232. To
explore the NGC 2232 stellar population in more detail, we downloaded
spectra of stars in the NGC 2232 field taken by the FAST instrument on
the 1.5m Tillinghast Telescope on 2001 January 31 and 2008 April 14.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 124 18652 Photometry catalogue for sources detected
in the NGC 2232 field
table2.dat 50 37 Spectroscopy of selected NGC 2232 sources
table3.dat 23 209 Confirmed and candidate cluster members with
Spitzer data
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See also:
IX/28 : ROSAT HRI Pointed Observations (1RXH) (ROSAT Team, 2000)
J/ApJS/188/242 : Variations on debris disks. II. (Kenyon+, 2010)
J/ApJ/653/675 : Spitzer 24µm photometry of A dwarfs (Su+, 2006)
J/ApJ/620/1010 : Spitzer 24µm photometry of A dwarfs (Rieke+, 2005)
http://heasarc.gsfc.nasa.gov/W3Browse/ : NASA HEASARC archive home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID Source identification number (G1)
7- 13 F7.4 deg RAdeg Right Ascension in decimal degrees (J2000)
15- 21 F7.4 deg DEdeg Declination in decimal degrees (J2000)
23- 28 F6.3 mag Vmag ?=0 V band magnitude
30- 35 F6.3 mag Jmag 2MASS J band magnitude
37- 42 F6.3 mag Hmag 2MASS H band magnitude
44- 49 F6.3 mag Ksmag 2MASS Ks band magnitude
51- 56 F6.3 mag 3.6mag ?=0 Spitzer/IRAC 3.6 micron band magnitude
58- 64 F7.3 mag e_3.6mag ?=-99 The 1σ error in 3.6mag
66- 71 F6.3 mag 4.5mag ?=0 Spitzer/IRAC 4.5 micron band magnitude
73- 79 F7.3 mag e_4.5mag ?=-99 The 1σ error in 4.5mag
81- 86 F6.3 mag 5.8mag ?=0 Spitzer/IRAC 5.8 micron band magnitude
88- 94 F7.3 mag e_5.8mag ?=-99 The 1σ error in 5.8mag
96-101 F6.3 mag 8.0mag ?=0 Spitzer/IRAC 8.0 micron band magnitude
103-109 F7.3 mag e_8.0mag ?=-99 The 1σ error in 8.0mag
111-116 F6.3 mag 24mag ?=0 Spitzer/MIPS 24 micron band magnitude
118-124 F7.3 mag e_24mag ?=-99 The 1σ error in 24mag
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID Source identification number (G1)
7- 13 F7.4 deg RAdeg Right ascension in decimal degree (J2000)
15- 21 F7.4 deg DEdeg Declination in decimal degrees (J2000)
23- 26 A4 --- SpT MK spectral type
28- 30 F3.1 --- e_SpT Uncertainty on SpT
32- 36 F5.2 0.1nm EW Hα equivalent width
38- 42 F5.2 0.1nm FWHM ?=99 Hα FWHM
44- 46 F3.1 ks-1 Cts ? ROSAT counts in X-ray
48- 50 A3 --- Mm? Yes or No for member
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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- 5 I5 --- ID Source identification number (G1)
7- 13 F7.4 deg RAdeg Right Ascension in decimal degrees (J2000)
15- 21 F7.4 deg DEdeg Declination in decimal degrees (J2000)
23 I1 --- Mm Member type (1)
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Note (1): Member type as follows:
1 = confirmed X-ray active cluster member;
2 = member from Claria (1972A&A....19..303C 1972A&A....19..303C);
3 = candidate member as determined from V/V-J colors, spectroscopy,
and proper motion;
4 = candidate member determined from J/J-Ks and J/J-H colors.
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Global notes:
Note (G1): The table includes sources with at least one detection in a Spitzer
IRAC or MIPS band. Sources are <Cl* NGC 2232 CPK NNNNN> in Simbad.
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 13-Dec-2010