J/ApJ/540/1016 K-band & NICMOS photometry of Trapezium Cluster (Luhman+, 2000)
The initial mass function of low-mass stars and brown dwarfs in young clusters.
Luhman K.L., Rieke G.H., Young E.T., Cotera A.S., Chen H., Rieke M.J.,
Schneider G., Thompson R.I.
<Astrophys. J. 540, 1016 (2000)>
=2000ApJ...540.1016L 2000ApJ...540.1016L
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Infrared sources ;
Magnitudes ; Spectra, infrared
Mission_Name: HST
Keywords: infrared: stars - stars: evolution - stars: formation -
stars: low-mass, brown dwarfs -
stars: luminosity function, mass function - stars: pre-main-sequence
Abstract:
We have obtained images of the Trapezium Cluster (140"x140";
0.3pc x 0.3pc) with the Hubble Space Telescope Near-Infrared Camera
and Multi-Object Spectrometer (NICMOS). Combining these data with new
ground-based K-band spectra (R=800) and existing spectral types and
photometry, we have constructed an H-R diagram and used it and other
arguments to infer masses and ages.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 189 320 Data for the Trapezium Cluster
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See also:
I/134 : Trapezium Multiple Systems (Salukvadze, 1978)
J/A+A/299/39 : Orion Trapezium area ROSAT PSPC obs. I. (Geier+, 1995)
J/AN/321/81 : Orion Trapezium area ROSAT PSPC obs. II. (Lohmann+, 2000)
J/AJ/117/1375 : Orion Trapezium cluster (Simon+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- [LRY2000] Sequential number
4- 6 A3 --- n_[LRY2000] [ghijkl ] Individual notes (1)
8- 14 A7 --- TCC Designations of McCaughrean & Stauffer,
1994AJ....108.1382M 1994AJ....108.1382M
15- 18 I4 --- [H97b] ? Designations of Hillenbrand,
1997AJ....113.1733H 1997AJ....113.1733H
19 A1 --- m_[H97b] [ab] Multiplicity index on [H97b]
21- 22 I2 h RAh Right ascension (J2000)
24- 25 I2 min RAm Right ascension (J2000)
27- 32 F6.3 s RAs Right ascension (J2000)
34 A1 --- DE- Declination sign (J2000)
35- 36 I2 deg DEd Declination (J2000)
38- 39 I2 arcmin DEm Declination (J2000)
41- 45 F5.2 arcsec DEs Declination (J2000)
47- 95 A49 --- SpTypel Previous spectral type determinations (2)
97-123 A27 --- IRType IR type (3)
125-133 A9 --- SpType Adopted spectral type
135-139 I5 K Teff ? Effective temperature
141-144 F4.2 mag AH ? Absorption in H band
146-155 F10.3 solLum Lbol ? Bolometric luminosity
157 A1 --- l_V-I Limit flag on V-I
158-162 F5.2 mag V-I ? V-I colour index (2)
164-168 F5.2 mag Imag ? I magnitude (2)
170 A1 --- l_m100-m160 Limit flag on 100-160
171-175 F5.2 --- m100-m160 ? F100W(0.8-1.4um)-F160W(1.4-1.8um)
colour index (4)
177-181 F5.2 mag m160mag ? F160W (1.4-1.8um) magnitude
183-187 F5.2 mag Kmag ? K magnitude from McCaughrean & Stauffer,
1994AJ....108.1382M 1994AJ....108.1382M
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Note (1): Individual notes:
g: Member of a binary system that is resolved in the optical
measurements while unresolved in the IR photometry.
h: The spectral type assigned to source 97 applies to the composite
system of 97, 100, and 101.
i: Within a diffraction spike.
j: Hillenbrand, 1997AJ....113.1733H 1997AJ....113.1733H
k: Optical measurement listed for TCC046 probably includes both
TCC039 and TCC046.
l: Optical measurement listed for TCC073 includes both
TCC070 and TCC073.
Note (2): References for spectral types:
T: Trumpler, 1931PASP...43..255T 1931PASP...43..255T
Par: Parenago, 1954, Cat. II/171
J: Johnson, 1965ApJ...142..964J 1965ApJ...142..964J
S: Strand, 1958ApJ...128...14S 1958ApJ...128...14S
LA: Levato & Abt, 1976PASP...88..712L 1976PASP...88..712L or
Abt & Levato, 1977PASP...89..797A 1977PASP...89..797A
CK: Cohen & Kuhi, 1979ApJS...41..743C 1979ApJS...41..743C
HT: Herbig & Terndrup, 1986ApJ...307..609H 1986ApJ...307..609H, and reference therein
P: C. F. Prosser & J. R. Stauffer 1993, private communication
vA: van Altena et al., 1988AJ.....95.1744V 1988AJ.....95.1744V
Eetal: Edwards et al., 1993AJ....106..372E 1993AJ....106..372E
Sam: Samuel 1993, Ph. D. thesis, Australian National Univ.
Ham: Hamilton 1994, Masters thesis, Wesleyan University
H: Hillenbrand, 1997AJ....113.1733H 1997AJ....113.1733H
Hp: L. A. Hillenbrand 2000, private comm. (Hp).
Note (3): The spectral type, K-band continuum veiling, and CO band head
strength measured from the K-band spectra. The veiling at K is defined
as r{K}=I2.2(IR excess)/I2.2(star), which is estimated from the
spectra. The strength of the CO band head is given as a percentage
increase in CO absorption over that of a dwarf of the same spectral
type.
Note (4): Blank entries indicate sources that are saturated or are too
close to bright stars to be measured. The one exception is TCC003,
which is not detected in the NICMOS data.
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Table 2: Low-Mass Candidates in IC 348
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ID RA (J2000) DE R-I I J-H H-KS KS
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435 03 44 30.33 +32 11 33.9 1.45 18.95 1.20 0.85 14.24
603 03 44 33.43 +32 10 29.8 19.93 1.01 0.65 15.17
609 03 44 44.92 +32 09 34.7 21.20 0.99 0.36 16.89
618 03 44 43.92 +32 08 34.3 21.47 0.94 0.47 16.89
624 03 44 26.30 +32 08 08.7 21.83 1.01 0.67 16.43
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Note: The optical and IR photometry is from the work of Luhman 1999,
Cat. J/ApJ/525/466 and Luhman et al. 1998ApJ...499..799L 1998ApJ...499..799L, respectively.
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History:
* 27-Nov-2000: From ApJ electronic version
* 05-Mar-2001: the designation "TCC" corrected for 2 entries of
table1 (dot removed in TCC names for entries 98 and 99)
(End) James Marcout, Patricia Bauer [CDS] 27-Nov-2000