J/A+A/710/A390 OH/IR stars in the inner Galactic bulge. I. (Olofsson+, 2026)
OH/IR stars in the inner Galactic bulge:
I. Colour, CO line, and stellar light curve characteristics.
Olofsson H., Khouri T., Muller S., Unnikrishnan R., Groenewegen M.A.T.,
Blommaert J.A.D.L., De Beck E., Kastner J.H., Maercker M., Patel N.,
Ryde N., Sargent B.A., Srinivasan S., Vlemmings W.H.T.
<Astron. Astrophys. 710, A390 (2026)>
=2026A&A...710A.390O 2026A&A...710A.390O (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Mass loss ; Radio lines ;
Photometry, millimetric/submm
Keywords: stars: AGB and post-AGB - circumstellar matter - stars: mass loss
Abstract:
Stars on the asymptotic giant branch (AGB) play important roles in a
number of astronomical contexts. To quantify these roles, it is
necessary to establish the mass-loss characteristics of stars as they
evolve up and beyond the AGB. We used an equidistant sample of 77 AGB
stars in the inner Galactic bulge, selected on the existence and
strength of OH1612 MHz maser emission, to obtain information on the
mass loss of O-rich AGB stars, and on its transformations in geometry
and kinematics that occur at the tip of the AGB. Observations of
circumstellar lines from several rotational transitions of 12CO, 13CO,
and C18O were performed with the Atacama Large
Millimeter/submillimeter Array (ALMA), and, for a sub-sample, with the
Atacama Pathfinder EXperiment telescope (APEX). The ALMA observations
also provide continuum data. Existing infrared photometry was used to
estimate colours and produce stellar light curves. Based on
mid-infrared colour, CO line, and near-infrared variability
characteristics, the objects were divided into four categories of
distinct stellar and/or circumstellar properties. Various
circumstellar CO line characteristics are presented and compared
between the categories, such as morphologies and extents of brightness
distributions (BDs), line profiles (LPs), line intensity ratios, and
kinematics. A majority of the objects form a homogenous group with
sharply, centrally peaked BDs and LPs of the soft-parabola type, while
the rest show extended and complex BDs and/or LPs with high-velocity
wings. The C18O line and ALMA continuum detection rates vary
significantly between the categories. CO line emission is also
detected from interaction zones where the expanding circumstellar gas
meets the interstellar medium. These data provide the foundation for
more detailed studies, including radiative transfer analyses of the CO
line and photometry data, on the evolution of stellar and
circumstellar characteristics of O-rich stars on the upper AGB and
beyond.
Description:
ALMA CO line and continuum intensities and kinematical data for 74
OH/IR stars in the inner Galactic Bulge.
For each object the systemic velocity (in LSR scale), gas expansion
velocity, total velocity width (only where applicable), and continuum
flux densities at 107, 233, and 338 GHz are given. For each object and
each CO line the flux densities and velocity-integrated flux densities
within apertures of 0.5", 1.0", 2.0", and 3.0" (except where otherwise
is stated) are given. O+22 = Olofsson et al., 2022A&A...665A..82O 2022A&A...665A..82O.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablec1a.dat 94 74 ALMA CO line and continuum data, part 1
tablec1b.dat 80 444 ALMA CO line and continuum data, part 2
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablec1a.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Source Source name
17- 20 I4 km/s vsys Systemic velocity (in LSR scale)
22- 23 I2 km/s vinfty Gas expansion velocity
25- 27 I3 km/s vtot ?=- Total velocity width
29- 32 F4.1 mJy Snu107 ?=- Continuum flux densities at 107GHz
34- 37 F4.1 mJy Snu233 ?=- Continuum flux densities at 233GHz
39- 42 F4.1 mJy Snu338 ?=- Continuum flux densities at 338GHz
44- 94 A51 --- Comm Comments
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablec1b.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Source Source name
17- 25 A9 --- Line Line
27- 31 F5.3 Jy Snu05 ?=- Line flux density within
aperture 0.5"
33- 37 F5.2 Jy.km/s int(Snu*dnu)05 ?=- Line velocity-integrated flux
density within aperture 0.5"
39- 43 F5.3 Jy Snu10 ?=- Line flux density within
aperture 1.0"
45- 49 F5.2 Jy.km/s int(Snu*dnu)10 ?=- Line velocity-integrated flux
density within aperture 1.0"
51- 55 F5.3 Jy Snu20 ?=- Line flux density within
aperture 2.0"
57- 62 F6.3 Jy.km/s int(Snu*dnu)20 ?=- Line velocity-integrated flux
density within aperture 2.0"
64- 68 F5.3 Jy Snu30 ?=- Line flux density within
aperture 3.0"
70- 74 F5.2 Jy.km/s int(Snu*dnu)30 ?=- Line velocity-integrated flux
density within aperture 3.0"
76- 80 F5.3 arcsec theta01 ?=- Angular extent at which the fit to
the AARP reaches 10% of its peak value
--------------------------------------------------------------------------------
Acknowledgements:
Hans Olofsson, hans.olofsson(at)chalmers.se
License: CC-BY-4.0
(End) Patricia Vannier [CDS] 27-May-2026