The GRAVITY young stellar object survey: II. First spatially resolved observations of the CO bandhead emission in a high-mass YSO
Artikel i vetenskaplig tidskrift, 2020

Context. The inner regions of the discs of high-mass young stellar objects (HMYSOs) are still poorly known due to the small angular scales and the high visual extinction involved. Aims. We deploy near-infrared spectro-interferometry to probe the inner gaseous disc in HMYSOs and investigate the origin and physical characteristics of the CO bandhead emission (2.3-2.4 m). Methods. We present the first GRAVITY/VLTI observations at high spectral (R = 4000) and spatial (mas) resolution of the CO overtone transitions in NGC2024 IRS 2. Results. The continuum emission is resolved in all baselines and is slightly asymmetric, displaying small closure phases (8). Our best ellipsoid model provides a disc inclination of 34 1, a disc major axis position angle (PA) of 166 1, and a disc diameter of 3:99 0:09 mas (or 1.69 0.04 au, at a distance of 423 pc). The small closure phase signals in the continuum are modelled with a skewed rim, originating from a pure inclination effect. For the first time, our observations spatially and spectrally resolve the first four CO bandheads. Changes in visibility, as well as differential and closure phases across the bandheads are detected. Both the size and geometry of the CO-emitting region are determined by fitting a bidimensional Gaussian to the continuum-compensated CO bandhead visibilities. The CO-emitting region has a diameter of 2.740:08 0:07 mas (1.16 0.03 au), and is located in the inner gaseous disc, well within the dusty rim, with inclination and PA matching the dusty disc geometry, which indicates that both dusty and gaseous discs are coplanar. Physical and dynamical gas conditions are inferred by modelling the CO spectrum. Finally, we derive a direct measurement of the stellar mass of M 14:7 M by combining our interferometric and spectral modelling results.

Techniques: spectroscopic

Methods: observational

Infrared: stars

Techniques: interferometric

Stars: massive

Stars: formation

Författare

A. Caratti o. Garatti

Dublin Institute for Advanced Studies

Max-Planck-Gesellschaft

University College Dublin

Rubén Fedriani

Dublin Institute for Advanced Studies

University College Dublin

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Galaktisk astrofysik

R. Garcia-Lopez

Max-Planck-Gesellschaft

Dublin Institute for Advanced Studies

University College Dublin

M. Koutoulaki

Dublin Institute for Advanced Studies

University College Dublin

European Southern Observatory (ESO)

K. Perraut

Université Grenoble Alpes

H. Linz

Max-Planck-Gesellschaft

W. Brandner

Max-Planck-Gesellschaft

P. J. V. Garcia

Universidade do Porto

Instituto Superior Tecnico

European Southern Observatory Santiago

L. Klarmann

Max-Planck-Gesellschaft

T. Henning

Max-Planck-Gesellschaft

L. Labadie

Universität zu Köln

J. Sanchez-Bermudez

Max-Planck-Gesellschaft

Universidad Nacional Autonoma de Mexico

B. Lazareff

Université Grenoble Alpes

E. F. van Dishoeck

Universiteit Leiden

Max-Planck-Gesellschaft

P. Caselli

Max-Planck-Gesellschaft

P. T. De Zeeuw

Max-Planck-Gesellschaft

Universiteit Leiden

A. Bik

Stockholms universitet

M. Benisty

European Southern Observatory Santiago

Université Grenoble Alpes

C. Dougados

Université Grenoble Alpes

Tom Ray

Dublin Institute for Advanced Studies

A. Amorim

Instituto Superior Tecnico

J. P. Berger

Université Grenoble Alpes

Y. Clénet

Observatoire de Paris

V. Coudé Du Foresto

Observatoire de Paris

G. Duvert

Université Grenoble Alpes

A. Eckart

Universität zu Köln

F. Eisenhauer

Max-Planck-Gesellschaft

F. Gao

Max-Planck-Gesellschaft

E. Gendron

Observatoire de Paris

R. Genzel

University of California

Max-Planck-Gesellschaft

S. Gillessen

Max-Planck-Gesellschaft

P. Gordo

Instituto Superior Tecnico

L. Jocou

Université Grenoble Alpes

M. Horrobin

Universität zu Köln

P. Kervella

Observatoire de Paris

S. Lacour

Observatoire de Paris

J. B. Le Bouquin

Université Grenoble Alpes

P. Léna

Observatoire de Paris

R. Grellmann

Universität zu Köln

T. Ott

Max-Planck-Gesellschaft

T. Paumard

Observatoire de Paris

G. Perrin

Observatoire de Paris

G. Rousset

Observatoire de Paris

S. Scheithauer

Max-Planck-Gesellschaft

J. Shangguan

Max-Planck-Gesellschaft

J. Stadler

Max-Planck-Gesellschaft

O. Straub

Max-Planck-Gesellschaft

C. Straubmeier

Universität zu Köln

E. Sturm

Max-Planck-Gesellschaft

W. F. Thi

Max-Planck-Gesellschaft

F. H. Vincent

Observatoire de Paris

F. Widmann

Max-Planck-Gesellschaft

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 635 L12

Ämneskategorier

Meteorologi och atmosfärforskning

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik

DOI

10.1051/0004-6361/202037583

Mer information

Senast uppdaterat

2020-05-19