J/ApJ/843/24 Hα interferometry obs. of the Be star 48 Per (Jones+, 2017)
The disk physical conditions of 48 Persei constrained by contemporaneous
Hα spectroscopy and interferometry.
Jones C.E., Sigut T.A.A., Grzenia B.J., Tycner C., Zavala R.T.
<Astrophys. J., 843, 24 (2017)>
=2017ApJ...843...24J 2017ApJ...843...24J
ADC_Keywords: Stars, Be ; Interferometry
Keywords: circumstellar matter; stars: emission-line, Be;
stars: individual (48 Per); stars: massive; stars: mass-loss;
techniques: interferometric; techniques: spectroscopic
Abstract:
We utilize a multi-step modeling process to produce synthetic
interferometric and spectroscopic observables, which are then compared
to their observed counterparts. Our extensive set of interferometric
observations of the Be star 48 Per, totaling 291 data points, were
obtained at the Navy Precision Optical Interferometer from 2006
November 07 to 23. Our models were further constrained by comparison
with contemporaneous Hα line spectroscopy obtained at the John
S. Hall Telescope at the Lowell Observatory on 2006 November 1.
Theoretical spectral energy distributions, SEDs, for 48 Per were
confirmed by comparison with observations over a wavelength regime of
0.4-60 µm from Touhami+ (2010PASP..122..379T 2010PASP..122..379T) and Vieira+
(2017MNRAS.464.3071V 2017MNRAS.464.3071V). Our best-fitting combined model from Hα
spectroscopy, Hα interferometry, and SED fitting has a power-law
density fall off, n, of 2.3 and an initial density at the stellar
surface of ρ0=1.0x10-11g/cm-3 with an inclination
constrained by Hα spectroscopy and interferometry of
45±5°. The position angle for the system, measured east from
north, is 114±18°. Our best-fit model shows that the disk
emission originates in a moderately large disk with a radius of 25 R*,
which is consistent with a disk mass of approximately 5x1024g or
3x10-10M*. Finally, we compare our results with previous studies of
48 Per by Quirrenbach+ (1997ApJ...479..477Q 1997ApJ...479..477Q) and find agreement,
whereas our disk size does not agree with Delaa+ (2011A&A...529A..87D 2011A&A...529A..87D),
based on a much smaller visibility set.
Description:
Our observations of 48 Per were obtained at the Navy Precision Optical
Interferometer (NPOI), located near Flagstaff, AZ, USA.
Typically, observations from up to five unique baselines are obtained
simultaneously; for this study, baseline lengths ranged from 18.9 to
64.4m. A total of 291 squared visibility measurements from a 150Å
wide spectral channel containing the Hα emission line (i.e.,
centered at 6563Å) of 48 Per were obtained at NPOI in 2006 Nov 7-23.
Objects:
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RA (ICRS) DE Designation(s)
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04 08 39.69 +47 42 45.0 48 Per = TYC 3332-2427-1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 45 291 Interferometric observations
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See also:
II/225 : Catalog of Infrared Observations, Edition 5 (Gezari+ 1999)
II/224 : Catalogue of Stellar Diameters (CADARS) (Pasinetti-Fracassini+ 2001)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
J/A+A/290/609 : Be stars near-IR excess (Dougherty+, 1994)
J/ApJ/689/461 : Circumstellar disk of χ Oph (Tycner+, 2008)
J/AJ/139/2269 : P Cyg Hα squared visibility (Balan+, 2010)
J/ApJ/814/159 : Hα interferometric visibilities of o Aqr (Sigut+, 2015)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 F11.3 d JD Observation Julian Date
13- 19 F7.3 10+6/rad u [-31.5/68.8] Spatial frequency u
in 10+6cycles/radian
21- 27 F7.3 10+6/rad v [-31.6/87.2] Spatial frequency v
in 10+6cycles/radian
29- 33 F5.3 --- VHa2 [0.5/1.1] Hα squared visibility
35- 39 F5.3 --- e_VHa2 [0.01/0.4] Uncertainty in VHa2
41- 45 A5 --- Baseline Baseline (1)
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Note (1): The baselines AC-AE, AC-AW, AW-W7, AC-W7, AE-W7 correspond to
lengths of 18.9, 22.2, 29.5, 51.6, and 64.4m, respectively.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Feb-2018