A measure of the size of the magnetospheric accretion region in TW Hydrae
Artikel i vetenskaplig tidskrift, 2020

Stars form by accreting material from their surrounding disks. There is a consensus that matter flowing through the disk is channelled onto the stellar surface by the stellar magnetic field. This is thought to be strong enough to truncate the disk close to the corotation radius, at which the disk rotates at the same rate as the star. Spectro-interferometric studies in young stellar objects show that hydrogen emission (a well known tracer of accretion activity) mostly comes from a region a few milliarcseconds across, usually located within the dust sublimation radius1–3. The origin of the hydrogen emission could be the stellar magnetosphere, a rotating wind or a disk. In the case of intermediate-mass Herbig AeBe stars, the fact that Brackett γ (Brγ) emission is spatially resolved rules out the possibility that most of the emission comes from the magnetosphere4–6 because the weak magnetic fields (some tenths of a gauss) detected in these sources7,8 result in very compact magnetospheres. In the case of T Tauri sources, their larger magnetospheres should make them easier to resolve. The small angular size of the magnetosphere (a few tenths of a milliarcsecond), however, along with the presence of winds9,10 make the interpretation of the observations challenging. Here we report optical long-baseline interferometric observations that spatially resolve the inner disk of the T Tauri star TW Hydrae. We find that the near-infrared hydrogen emission comes from a region approximately 3.5 stellar radii across. This region is within the continuum dusty disk emitting region (7 stellar radii across) and also within the corotation radius, which is twice as big. This indicates that the hydrogen emission originates in the accretion columns (funnel flows of matter accreting onto the star), as expected in magnetospheric accretion models, rather than in a wind emitted at much larger distance (more than one astronomical unit).

Författare

R. Garcia-Lopez

Max-Planck-Gesellschaft

Dublin Institute for Advanced Studies

University College Dublin

A. Natta

Dublin Institute for Advanced Studies

A. Caratti o. Garatti

Dublin Institute for Advanced Studies

University College Dublin

Max-Planck-Gesellschaft

Tom Ray

Dublin Institute for Advanced Studies

Rubén Fedriani

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

Dublin Institute for Advanced Studies

M. Koutoulaki

European Southern Observatory (ESO)

Dublin Institute for Advanced Studies

L. Klarmann

Max-Planck-Gesellschaft

K. Perraut

Université Grenoble Alpes

J. Sanchez-Bermudez

Max-Planck-Gesellschaft

Universidad Nacional Autonoma de Mexico

M. Benisty

Université Grenoble Alpes

Universidad de Chile (UCH)

C. Dougados

Université Grenoble Alpes

L. Labadie

Universität zu Köln

W. Brandner

Max-Planck-Gesellschaft

P. J. V. Garcia

European Southern Observatory Santiago

Instituto Superior Tecnico

Universidade do Porto

T. Henning

Max-Planck-Gesellschaft

P. Caselli

Max-Planck-Gesellschaft

G. Duvert

Université Grenoble Alpes

T. De Zeeuw

Universiteit Leiden

Max-Planck-Gesellschaft

R. Grellmann

Universität zu Köln

R. Abuter

European Southern Observatory (ESO)

A. Amorim

Instituto Superior Tecnico

Universidade de Lisboa

M. Bauböck

Max-Planck-Gesellschaft

J. P. Berger

European Southern Observatory (ESO)

Université Grenoble Alpes

H. Bonnet

European Southern Observatory (ESO)

A. Buron

Max-Planck-Gesellschaft

Y. Clénet

Université de recherche Paris Sciences et Lettres

V. Coudé Du Foresto

Université de recherche Paris Sciences et Lettres

W. J. De Wit

European Southern Observatory Santiago

A. Eckart

Universität zu Köln

Max-Planck-Gesellschaft

F. Eisenhauer

Max-Planck-Gesellschaft

M. Filho

Universidade do Porto

Instituto Superior Tecnico

European Southern Observatory Santiago

F. Gao

Max-Planck-Gesellschaft

C. E. Garcia Dabo

European Southern Observatory (ESO)

E. Gendron

Université de recherche Paris Sciences et Lettres

R. Genzel

University of California

Max-Planck-Gesellschaft

S. Gillessen

Max-Planck-Gesellschaft

M. Habibi

Max-Planck-Gesellschaft

X. Haubois

European Southern Observatory Santiago

F. Haussmann

Max-Planck-Gesellschaft

S. Hippler

Max-Planck-Gesellschaft

Z. Hubert

Université Grenoble Alpes

M. Horrobin

Universität zu Köln

Alejandra Jimenez-Rosales

Max-Planck-Gesellschaft

L. Jocou

Université Grenoble Alpes

P. Kervella

Université de recherche Paris Sciences et Lettres

J. Kolb

European Southern Observatory Santiago

S. Lacour

Université de recherche Paris Sciences et Lettres

J. B. Le Bouquin

Université Grenoble Alpes

P. Léna

Université de recherche Paris Sciences et Lettres

T. Ott

Max-Planck-Gesellschaft

T. Paumard

Université de recherche Paris Sciences et Lettres

G. Perrin

Université de recherche Paris Sciences et Lettres

O. Pfuhl

European Southern Observatory (ESO)

A. Ramirez

European Southern Observatory (ESO)

C. Rau

Max-Planck-Gesellschaft

G. Rousset

Université de recherche Paris Sciences et Lettres

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

E. F. van Dishoeck

Universiteit Leiden

Max-Planck-Gesellschaft

F. H. Vincent

Université de recherche Paris Sciences et Lettres

S. von Fellenberg

Max-Planck-Gesellschaft

F. Widmann

Max-Planck-Gesellschaft

E. Wieprecht

Max-Planck-Gesellschaft

M. Wiest

Universität zu Köln

E. Wiezorrek

Max-Planck-Gesellschaft

Julien Woillez

European Southern Observatory (ESO)

S. Yazici

Max-Planck-Gesellschaft

Universität zu Köln

G. Zins

European Southern Observatory Santiago

Nature

0028-0836 (ISSN) 1476-4687 (eISSN)

Vol. 584 7822 547-550

Ämneskategorier

Meteorologi och atmosfärforskning

Fusion, plasma och rymdfysik

DOI

10.1038/s41586-020-2613-1

Mer information

Senast uppdaterat

2020-11-10