J/ApJ/698/1989 Spitzer survey of NGC 2451 (Balog+, 2009)
Spitzer/IRAC-MIPS survey of NGC 2451A and B: debris disks at 50-80 million
years.
Balog Z., Kiss L.L., Vinko J., Rieke G.H., Muzerolle J., Gaspar A.,
Young E.T., Gorlova N.
<Astrophys. J., 698, 1989-2013 (2009)>
=2009ApJ...698.1989B 2009ApJ...698.1989B
ADC_Keywords: Clusters, open ; Photometry, UBVRI ; Photometry, infrared ;
Stars, luminous
Keywords: circumstellar matter - infrared: stars - open clusters and
associations: individual (NGC 2451) - planetary systems:
protoplanetary disks
Abstract:
We present a Spitzer IRAC and MIPS survey of NGC 2451A and B, two open
clusters in the 50-80Myr age range. We complement these data with
extensive ground-based photometry and spectroscopy to identify the
cluster members in the Spitzer survey field. We find only two members
with 8um excesses. The incidence of excesses at 24um is much higher,
i.e., 11 of 31 solar-like stars and 1 of 7 early-type (A) stars. This
work nearly completes the debris disk surveys with Spitzer of clusters
in the 30-130Myr range. This range is of interest because it is when
large planetesimal collisions may have still been relatively common
(as indicated by the one that led to the formation of the Moon during
this period of the evolution of the solar system). We review the full
set of surveys and find that there are only three possible cases out
of about 250 roughly solar-mass stars where very large excesses
suggest that such collisions have occurred recently.
Description:
Observations of NGC 2451 were obtained on 2004 March 2 with IRAC. The
IRAC survey covers about 0.6deg2 centered on HD 63032, a K2.5Ib
star. The MIPS 24um survey was obtained on 2004 April 11. It covers
about 0.8deg2 centered on the same position as the IRAC survey.
The optical observations, through Johnson-Cousins UBVRI filters, were
made with the SITe 2048-6 CCD camera attached to the 1.5m telescope at
Cerro Tololo Inter-American Observatory (CTIO) on 2003 January 22, 23,
and 24.
We acquired AAOmega spectrograph data using the Anglo-Australian
Telescope at Siding Spring, Australia on three nights, 2008 February
15, 16, and 17.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 128 70 UBVRIJHK photometry of the members of NGC2451A
table4.dat 128 131 UBVRIJHK photometry of the members of NGC2451B
table5.dat 89 70 Spitzer 3.6-24um photometry of members of NGC2451A
table6.dat 89 131 Spitzer 3.6-24um photometry of members of NGC2451B
table7.dat 46 14 Measured and predicted photospheric (K-[24])0
colors of cluster members with 24um excesses
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/A+A/402/571 : X-ray study of NGC 2451 A and B. (Huensch+ 2003)
J/AJ/122/1486 : NGC 2451A proper motions and membership (Platais+, 2001)
J/A+A/341/469 : Geneva photometry of NGC 2451 and HR 2968 (Carrier+ 1999)
Byte-by-byte Description of file: table[34].dat
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Bytes Format Units Label Explanations
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1 A1 --- Ref [HP] Membership reference (1)
3- 11 F9.5 deg RAdeg Right Ascension in degrees (J2000)
13- 21 F9.5 deg DEdeg Declination in degrees (J2000)
23- 24 I2 --- e24 [6,19]? The 24µm excess source from Table 7
26- 31 F6.3 mag Umag ? The Johnson U band magnitude
33- 37 F5.3 mag e_Umag ? The 1σ error in Umag
39- 44 F6.3 mag Bmag ? The Johnson B band magnitude
46- 50 F5.3 mag e_Bmag ? The 1σ error in Bmag
52- 57 F6.3 mag Vmag The Johnson V band magnitude
59- 63 F5.3 mag e_Vmag ? The 1σ error in Vmag
65- 70 F6.3 mag Rcmag ? The Cousins R band magnitude
72- 76 F5.3 mag e_Rcmag ? The 1σ error in Rcmag
78- 83 F6.3 mag Icmag ? The Cousins I band magnitude
85- 89 F5.3 mag e_Icmag ? The 1σ error in Icmag
91- 96 F6.3 mag Jmag 2MASS Johnson J band magnitude
98-102 F5.3 mag e_Jmag ? The 1σ error in Jmag
104-109 F6.3 mag Hmag 2MASS Johnson H band magnitude
111-115 F5.3 mag e_Hmag ? The 1σ error in Hmag
117-122 F6.3 mag Ksmag 2MASS Johnson Ks band magnitude
124-128 F5.3 mag e_Ksmag ? The 1σ error in Ksmag
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Note (1): Reference as follows:
P = Platais et al. (2001, Cat. J/AJ/122/1486;
<Cl* NGC 2451 PKB NNNN> in Simbad);
H = Hunsch et al. (2003, Cat. J/A+A/402/571; <[HWS2003] XNNN> in Simbad).
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Byte-by-byte Description of file: table[56].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Ref [HP] Membership reference (1)
3- 11 F9.5 deg RAdeg Right Ascension in degrees (J2000)
13- 21 F9.5 deg DEdeg Declination in degrees (J2000)
23- 24 I2 --- e24 [6,19]? The 24µm excess source from Table 7
26- 31 F6.3 mag [3.6] ? Spitzer/IRAC 3.6µm band magnitude
33- 37 F5.3 mag e_[3.6] ? The 1σ error in 3.6µm mag
39- 44 F6.3 mag [4.5] ? Spitzer/IRAC 4.5µm band magnitude
46- 50 F5.3 mag e_[4.5] ? The 1σ error in 4.5µm mag
52- 57 F6.3 mag [5.8] ? Spitzer/IRAC 5.8µm band magnitude
59- 63 F5.3 mag e_[5.8] ? The 1σ error in 5.8µm mag
65- 70 F6.3 mag [8.0] ? Spitzer/IRAC 8.0µm band magnitude
72- 76 F5.3 mag e_[8.0] ? The 1σ error in 8.0µm mag
78- 83 F6.3 mag [24] ? Spitzer/MIPS 24µm band magnitude
85- 89 F5.3 mag e_[24] ? The 1σ error in 24µm mag
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Note (1): Reference as follows:
P = Platais et al. (2001, Cat. J/AJ/122/1486; <Cl* NGC 2451 PKB NNNN> in
Simbad);
H = Hunsch et al. (2003, Cat. J/A+A/402/571; <[HWS2003] XNNN> in Simbad).
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- e24 [6-19] Identification number
(<[BKV2009] NN> in Simbad)
4 A1 --- Comp [AB] NGC 2451 component
6- 14 F9.5 deg RAdeg Right ascension in decimal degrees (J2000)
16- 24 F9.5 deg DEdeg Declination in decimal degrees (J2000)
26- 30 F5.3 mag K-[24] Measured (K-[24])0 color index
32- 36 F5.3 mag e_K-[24] K-[24] uncertainty
38- 43 F6.3 mag K-[24]p Predicted photospheric K-[24] color index
45- 46 I2 --- Sigma σ significance of the excess (1)
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Note (1): The significance was calculated using the photometric errors
and the rms around this locus.
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Nomenclature note:
Tables 3-6: stars are <[BKV2009] DDD.ddddd+DD.ddddd> in Simbad.
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 17-Jun-2011