eta Carinae: high angular resolution continuum, H30 alpha and He30 alpha ALMA images

Autor(es)

Abraham, Zulema ^[1] ; Beaklini, Pedro P. B. ^{[1, 2]} ; Cox, Pierre ^[3] ; Falceta-Goncalves, Diego ^[4] ; Nyman, Lars-Ake ^[5]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfet, Rua Matao 1226, BR-05508090 Sao Paulo - Brazil

^[2] Natl Radio Astron Observ, 1003 Lopezville Rd, Socorro, NM 87801 - USA

^[3] UPMC Univ Paris 6, Sorbonne Univ, Inst Astrophys Paris, 98Bis Blvd Arago, F-75014 Paris - France

^[4] Univ Sao Paulo, Escola Artes Ciencias & Humanidades, Rua Arlindo Bettio 1000, BR-03828000 Sao Paulo, SP - Brazil

^[5] European Southern Observ, Alonso de Cordoba 3107, Vitacura - Chile

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 499, n. 2, p. 2493-2512, DEC 2020.
• Citações Web of Science: 0

Resumo

We present images of eta Carinae in the recombination lines H30 alpha and He30 alpha and the underlying continuum with 50 mas resolution (110 au), obtained with ALMA. For the first time, the 230 GHz continuum image is resolved into a compact core, coincident with the binary system position, and aweaker extended structure to theNWof the compact source. Iso-velocity images of the H30 alpha recombination line show at least 16 unresolved sources with velocities between -30 and -65 km s(-1) distributed within the continuum source. A NLTE model, with density and temperature of the order of 10(7) cm(-3) and 10(4) K, reproduce both the observed H30 alpha line profiles and their underlying continuum flux densities. Three of these sources are identified with Weigelt blobs D, C, and B; estimating their proper motions, we derive ejection times (in years) of 1952.6, 1957.1, and 1967.6, respectively, all of which are close to periastron passage. Weaker H30 alpha line emission is detected at higher positive and negative velocities, extending in the direction of the Homunculus axis. The He30 alpha recombination line is also detected with the same velocity of the narrow H30 alpha line. Finally, the close resemblance of the H30 alpha image with that of an emission line that was reported in the literature as HCO+(4-3) led us to identify this line as H40 delta instead, an identification that is further supported by modelling results. Future observations will enable to determine the proper motions of all the compact sources discovered in the new high angular resolution data of eta Carinae. (AU)

• Processo FAPESP: 11/51676-9 - LLAMA: um radiotelescópio para ondas mm/sub-mm nos Andes, em colaboração com a Argentina
• Beneficiário: Jacques Raymond Daniel Lépine
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/07460-0 - Alvos para o LLAMA: estudo da variabilidade de rádio fontes em 43 GHz (banda 1) e busca por correlação com imagens interferométricas
• Beneficiário: Pedro Paulo Bonetti Beaklini
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado