The circumstellar environment of HD 50138 revealed by VLTI/AMBER at high angular resolution

DC FieldValueLanguage
dc.contributor.authorKoutoulaki, Maria-Kalliopi-
dc.contributor.authorGarcia Lopez, R.-
dc.contributor.authorNatta, A.-
dc.contributor.authorCoffey, Deirdre-
dc.contributor.authoret al.-
dc.date.accessioned2019-10-15T15:33:22Z-
dc.date.available2019-10-15T15:33:22Z-
dc.date.copyright2018 ESOen_US
dc.date.issued2018-06-22-
dc.identifier.citationAstronomy and Astrophysicsen_US
dc.identifier.issn0004-6361-
dc.identifier.urihttp://hdl.handle.net/10197/11144-
dc.description.abstractContext. HD 50138 is a Herbig B[e] star with a circumstellar disc detected at infrared and millimeter wavelength. Its brightness makes it a good candidate for near-infrared interferometry observations. Aims. We aim to resolve, spatially and spectrally, the continuum and hydrogen emission lines in the 2.12–2.47 micron region, to shed light on the immediate circumstellar environment of the star. Methods. VLTI/AMBER K-band observations provide spectra, visibilities, differential phases, and closure phases along three long baselines for the continuum, and H I emission in Brγ and five high-n Pfund lines. By computing the pure line visibilities, we derive the angular size of the different line-emitting regions. A simple local thermodynamic equilibrium (LTE) model was created to constrain the physical conditions of H I emitting region. Results. The continuum region cannot be reproduced by a geometrical two-dimensional (2D) elongated Gaussian fitting model. We estimate the size of the region to be 1 au. We find the detected hydrogen lines (Brγ and Pfund lines) come from a more compact region of size 0.4 au. The Brγ line exhibits an S-shaped differential phase, indicative of rotation. The continuum and Brγ line closure phases show offsets of ~ −25 ± 5° and 20 ± 10° respectively. This is evidence of an asymmetry in their origin, but with opposing directions. We find that we cannot converge on constraints for the HI physical parameters without a more detailed model. Conclusions. Our analysis reveals that HD 50138 hosts a complex circumstellar environment. Its continuum emission cannot be reproduced by a simple disc brightness distribution. Similarly, several components must be evoked to reproduce the interferometric observables within the Brγ line. Combining the spectroscopic and interferometric data of the Brγ and Pfund lines favours an origin in a wind region with a large opening angle. Finally, although we cannot exclude the possibility that HD 50138 is a young star our results point to an evolved source.en_US
dc.description.sponsorshipEuropean Commission Horizon 2020en_US
dc.description.sponsorshipEuropean Research Councilen_US
dc.description.sponsorshipIrish Research Councilen_US
dc.description.sponsorshipScience Foundation Irelanden_US
dc.language.isoenen_US
dc.publisherEDP Sciencesen_US
dc.subjectInterferometricen_US
dc.subjectHD 50138en_US
dc.subjectWindsen_US
dc.subjectOutflowsen_US
dc.subjectEmission-lineen_US
dc.subjectPre-main sequenceen_US
dc.subjectInfrareden_US
dc.titleThe circumstellar environment of HD 50138 revealed by VLTI/AMBER at high angular resolutionen_US
dc.typeJournal Articleen_US
dc.internal.authorcontactotherdeirdre.coffey@ucd.ieen_US
dc.statusPeer revieweden_US
dc.identifier.volume614en_US
dc.citation.otherA90en_US
dc.identifier.doi10.1051/0004-6361/201832814-
dc.neeo.contributorKoutoulaki|Maria-Kalliopi|aut|-
dc.neeo.contributorGarcia Lopez|R.|aut|-
dc.neeo.contributorNatta|A.|aut|-
dc.neeo.contributorCoffey|Deirdre|aut|-
dc.neeo.contributoret al.||aut|-
dc.description.othersponsorshipESO Fellowship Programmeen_US
dc.date.updated2019-09-06T12:29:30Z-
dc.identifier.grantidGOIPG/2016/769-
dc.identifier.grantid13/ERC/12907-
dc.identifier.grantid743029-
item.grantfulltextopen-
item.fulltextWith Fulltext-
Appears in Collections:Physics Research Collection
Files in This Item:
File Description SizeFormat 
aa32814-18.pdf547.43 kBAdobe PDFDownload
Show simple item record

SCOPUSTM   
Citations 50

2
Last Week
0
Last month
checked on Apr 1, 2020

Page view(s)

221
Last Week
6
Last month
checked on Apr 5, 2020

Download(s)

64
checked on Apr 5, 2020

Google ScholarTM

Check

Altmetric


This item is available under the Attribution-NonCommercial-NoDerivs 3.0 Ireland. No item may be reproduced for commercial purposes. For other possible restrictions on use please refer to the publisher's URL where this is made available, or to notes contained in the item itself. Other terms may apply.