J/ApJ/653/657 Spectroscopic observations of Herbig Ae/Be stars (Manoj+, 2006)
Evolution of emission-line activity in intermediate-mass young stars.
Manoj P., Bhatt H.C., Maheswar G., Muneer S.
<Astrophys. J., 653, 657-674 (2006)>
=2006ApJ...653..657M 2006ApJ...653..657M
ADC_Keywords: Stars, pre-main sequence ; Photometry ; Equivalent widths
Keywords: circumstellar matter - planetary systems: protoplanetary disks -
stars: emission-line, Be - stars: pre-main-sequence -
techniques: spectroscopic
Abstract:
We present optical spectra of 45 intermediate-mass Herbig Ae/Be stars.
Together with the multiepoch spectroscopic and photometric data
compiled for a large sample of these stars and ages estimated for
individual stars by using pre-main-sequence evolutionary tracks, we
have studied the evolution of emission-line activity in them. We find
that, on average, the Hα emission line strength decreases with
increasing stellar age in Herbig Ae/Be stars, indicating that the
accretion activity gradually declines during the pre-main-sequence
phase.
Description:
Optical CCD spectra centered at the Hα line (lambda∼6252Å)
were obtained for 45 stars in our sample with the Optomechanics
Research (OMR) spectrograph on the 2.34m Vainu Bappu Telescope (VBT)
at the Vainu Bappu Observatory, Kavalur, India, and with the Hanle
Faint Object Spectrograph (HFOSC) on the 2m Himalayan Chandra
Telescope at the Indian Astronomical Observatory, Hanle, India.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 50 91 Basic data for 91 Herbig Ae/Be stars compiled
from literature
table2.dat 65 45 Log of spectroscopic observations object
table3.dat 50 91 Masses and ages of Herbig Ae/Be stars
table4.dat 56 91 Hα equivalent widths of Herbig Ae/Be stars
table5.dat 54 62 2MASS magnitudes of Herbig Ae/Be stars
refs.dat 68 39 References
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See also:
J/AJ/106/656 : Herbig Ae/Be stars (Brooke+, 1993)
J/A+AS/104/315 : Member of Herbig Ae/Be stellar group (The+ 1994)
J/A+AS/111/399 : Polarization variability in Herbig Ae/Be stars (Jain+, 1995)
J/A+AS/136/429 : Herbig Ae/Be stars candidates (Corporon+ 1999)
J/AJ/126/2971 : UBVRI photometry of 131 Herbig Ae/Be (Vieira+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object name
12- 16 F5.2 mag Vmag Johnson V band magnitude
18- 21 F4.2 mag B-V Johnson (B-V) color index
23- 27 F5.2 mag Rmag ?=99.990 Johnson R band magnitude
29- 30 I2 --- r_Rmag The photometry reference in refs.dat file
32- 39 A8 --- SpType MK spectral type
41- 42 I2 --- r_SpType Reference for SpType in refs.dat file
44- 47 I4 pc Dist Distance
49- 50 I2 --- r_Dist Reference on Dis in refs.dat file
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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- 12 A12 --- Name Object name
14- 15 I2 h RAh Right ascension (J2000)
17- 18 I2 min RAm Right ascension (J2000)
20- 23 F4.1 s RAs Right ascension (J2000)
25 A1 --- DE- Declination sign (J2000)
26- 27 I2 deg DEd Declination (J2000)
29- 30 I2 arcmin DEm Declination (J2000)
32- 33 I2 arcsec DEs Declination (J2000)
35- 44 A10 "YYYY/DD/MM" Obs.date Observation date
46- 50 A5 "h:m" Obs.time UT start of observation
52- 55 I4 s ExpTime Exposure Time
57- 65 A9 --- Spect/Inst Spectrograph/Instrument
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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- 10 A10 --- Name Object name
12- 15 F4.2 [K] logT Log of the effective temperature
17- 20 F4.2 mag E(B-V) The (B-V) color excess
22- 26 F5.2 mag R Ratio of total-to-selective extinction
28- 32 F5.2 mag AV The V band extinction
34- 37 F4.2 [solLum] logL Log of the luminosity
39 A1 --- l_Mass Limit flag on Mass
40- 43 F4.2 solMass Mass Derived mass
45 A1 --- l_Age Limit flag on Age
46- 50 F5.2 Myr Age Derived age
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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- 10 A10 --- Name Object name (1)
12- 18 F7.2 0.1nm Now ? Hα equivalent width from this work
20- 25 F6.2 0.1nm HB88 ? Herbig & Bell (1988, Cat. V/73)
Hα equivalent width
27- 33 F7.2 0.1nm Her04 ? Hernandez et al. (2004AJ....127.1682H 2004AJ....127.1682H)
Hα equivalent width
35- 40 F6.2 0.1nm CR98 ? Corcoran & Ray (1998A&A...331..147C 1998A&A...331..147C)
Hα equivalent width
42- 48 F7.2 0.1nm AVD05 ? Acke et al. (2005A&A...436..209A 2005A&A...436..209A)
Hα equivalent width
50- 56 F7.2 0.1nm BPL96 ? Reipurth et al. (1996A&AS..120..229R 1996A&AS..120..229R)
Hα equivalent width
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Note (1): All equivalent widths given in Angstroms. Negative values of
equivalent widths signifies emission.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object name
12- 27 A16 --- 2MASS The 2MASS designation (HHMMSSss+DDMMSSs)
29- 33 F5.2 mag Jmag 2MASS J band magnitude
35- 39 F5.2 mag Hmag 2MASS H band magnitude
41- 44 F4.2 mag Ksmag 2MASS Ks band magnitude
46- 49 F4.2 mag Del(H-Ks) Intrinsic (H-Ks) color excess (1)
51- 54 F4.2 mag e_Del(H-Ks) Error on Del(H-Ks)
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Note (1): Due to thermal emission from the inner disk by subtracting the
photospheric color and color due to interstellar and large scale
circumstellar reddening from the observed colors.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 45 A22 --- Aut Author's name
47- 68 A22 --- Com Comments
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History:
* 10-Nov-2008: From electronic version of the journal
* 05-Feb-2014: In table4, label logM corrected into M
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 31-Jul-2008