| Full text | |
| Author(s): |
Abraham, Zulema
;
Beaklini, Pedro P. B.
;
Cox, Pierre
;
Falceta-Goncalves, Diego
;
Nyman, Lars-Ake
Total Authors: 5
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 499, n. 2, p. 20-pg., 2020-12-01. |
| Abstract | |
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) | |
| FAPESP's process: | 14/07460-0 - Targets for LLAMA: Study of variability of radio sources at 43 GHz (Band 1) and search for correlation with interferometric images. |
| Grantee: | Pedro Paulo Bonetti Beaklini |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 11/51676-9 - Llama: um radiotelescopio para ondas mm/sub-mm nos andes, em colaboracao com a argentina. |
| Grantee: | Jacques Raymond Daniel Lépine |
| Support Opportunities: | Research Projects - Thematic Grants |