A Mid-infrared Interferometric Study of the Circumstellar Environment of Dusty OH/IR Stars with VLTI/MIDI

AbstractHD 62623 is one of the very few A-type supergiants showing the B[e] phenomenon. We studied the geometry of its circumstellar envelope in the mid-infrared using the VLTI/MIDI instrument. Using the radiative transfer code MC3D, we managed to model it as a dusty disk with an inner radius of 3.85 AU, an inclination angle of 60°, and a mass of 2 × 10−7M⊙. It is the first time that the dusty disk inner rim of a supergiant star exhibiting the B[e] phenomenon is significantly constrained. The inner gaseous envelope likely contributes up to 20% to the total N band flux and acts like a reprocessing disk. Finally, the hypothesis of a stellar wind deceleration by the companion gravitational effect remains the most probable case since the bi-stability mechanism is not efficient for this star.

Download Full-text

Mid-Infrared Observations of the Mira Circumstellar Environment

The Astrophysical Journal ◽

10.1086/322737 ◽

2001 ◽

Vol 556 (1) ◽

pp. L47-L50 ◽

Cited By ~ 15

Author(s):

Massimo Marengo ◽

Margarita Karovska ◽

Giovanni G. Fazio ◽

Joseph L. Hora ◽

William F. Hoffmann ◽

...

Keyword(s):

Mid Infrared ◽

Infrared Observations ◽

Circumstellar Environment

Download Full-text

Astrometric VLBI Observations of the Galactic LPVs, Miras, and OH/IR stars

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317009449 ◽

2017 ◽

Vol 13 (S336) ◽

pp. 365-368 ◽

Cited By ~ 1

Author(s):

Akiharu Nakagawa ◽

Tomoharu Kurayama ◽

Gabor Orosz ◽

Ross A. Burns ◽

Tomoaki Oyama ◽

...

Keyword(s):

Spatial Distribution ◽

Mass Loss ◽

Simulation Study ◽

Galactic Dynamics ◽

Vlbi Observation ◽

Mid Infrared ◽

Vlbi Observations ◽

Ir Stars ◽

Distance Indicator ◽

Absolute Magnitudes

AbstractStudies of Galactic LPVs based on astrometric VLBI are presented. We use a VLBI array, “VERA”, to measure parallaxes and calibrate the K-band period luminosity relation (PLR) of the Galactic Miras. Since the PLR offers a distance indicator, its calibration is crucial to reveal their spatial distribution. Parallaxes of dozens of LPVs are presented. For the longer period stars, the mass-loss is high and the stars are obscured and recognized as OH/IR stars. We estimated mid-infrared absolute magnitudes of dozens of OH/IR stars and found that they show a loose concentration around −14 mag at λ of 11.6 μm, indicating an existence of PLR for OH/IR stars. Astrometry of OH/IR stars will also help us to study non-steady spiral arms as proposed from the latest simulation study of the galactic dynamics. We will start astrometric VLBI observation of two OH/IR stars NSV25875 and OH127.8+0.0 at 43 GHz with VERA.

Download Full-text

OH/IR stars versus YSOs in infrared photometric surveys

Proceedings of the International Astronomical Union ◽

10.1017/s1743921318007901 ◽

2018 ◽

Vol 14 (S343) ◽

pp. 454-455

Author(s):

Cécile Loup ◽

Mark Allen ◽

Ariane Lançon ◽

Anais Oberto

Keyword(s):

Selection Criteria ◽

Far Infrared ◽

High Mass ◽

Agb Stars ◽

Infrared Photometry ◽

Mid Infrared ◽

Ir Stars ◽

High Mass Loss ◽

Infrared Surveys ◽

Methanol Masers

AbstractAGB stars play a major role in the chemical evolution of the galaxies. It thus is important to establish reliable photometric selection criteria to count them, especially AGB stars at the last stages of AGB evolution like OH/IR stars. Here, we have identified about 1500 OH/IR stars and 500 YSOs with methanol masers, in all major mid– and far–infrared surveys (IRAS, MSX, AKARI, WISE, GLIMPSE, and Hi–Gal). We show that AGB stars with high mass-loss rates cannot be disentagled from YSOs with only mid–infrared photometry; far–infrared photometry is essential. In the region observed by GLIMPSE, we show that the proportion of AGB stars has been severely underestimated in previous works: about 70% of “intrinsically” red objects in GLIMPSE are AGB stars rather than YSOs.

Download Full-text

AN INTERFEROMETRIC STUDY OF THE FOMALHAUT INNER DEBRIS DISK. II. KECK NULLER MID-INFRARED OBSERVATIONS

The Astrophysical Journal ◽

10.1088/0004-637x/763/2/119 ◽

2013 ◽

Vol 763 (2) ◽

pp. 119 ◽

Cited By ~ 22

Author(s):

B. Mennesson ◽

O. Absil ◽

J. Lebreton ◽

J.-C. Augereau ◽

E. Serabyn ◽

...

Keyword(s):

Mid Infrared ◽

Infrared Observations ◽

Interferometric Study ◽

Debris Disk

Download Full-text

The OH/IR star population at the centre of the Galaxy

Symposium - International Astronomical Union ◽

10.1017/s0074180900222663 ◽

2002 ◽

Vol 206 ◽

pp. 335-338

Author(s):

Roberto Ortiz ◽

Alain Omont ◽

Mathias Schultheis ◽

Eric Copet ◽

Harm J. Habing ◽

...

Keyword(s):

Near Infrared ◽

Galactic Plane ◽

High Spatial Resolution ◽

Agb Stars ◽

Mid Infrared ◽

Infrared Observations ◽

Ir Stars ◽

The Galaxy ◽

Bulge Region ◽

Infrared Data

In the last years various OH surveys at 1612 MHz have been carried out in the galactic bulge region with high spatial resolution (Lindqvist et al. 1992; Sevenster et al. 1997; Sjouwerman et al. 1998) which have resulted in the detection of over five hundred double-peaked objects commonly associated with oxygen-rich AGB stars. More recently, the ISOGAL survey, which is part of the ISO mission, scanned several regions along the galactic plane, including the inner bulge, at 6.8 and 15 micron wavelengths. In this work we report an analysis of 104 OH/IR stars in the bulge, based on near and mid-infrared observations. Mass-loss rates, luminosities and masses are determined for a sub-sample of stars, for which near-infrared data are available in the literature.

Download Full-text