| Full text | |
| Author(s): Show less - |
Gregorio-Hetem, J.
[1]
;
Navarete, F.
[1]
;
Hetem, A.
[2]
;
Santos-Silva, T.
[1]
;
Galli, P. A. B.
[3]
;
Fernandes, B.
[1]
;
Montmerle, T.
[4]
;
Jatenco-Pereira, V
[1]
;
Fernandes, M. Borges
[5]
;
Perottoni, H. D.
[1]
;
Schoenell, W.
[6]
;
Ribeiro, T.
[7]
;
Kanaan, A.
[8]
Total Authors: 13
|
| Affiliation: | [1] Univ Sao Paulo, IAG, Rua Matao 1226, BR-05508090 Sao Paulo - Brazil
[2] UFABC Fed Univ ABC, Av Estados 5001, BR-09210580 Santo Andre, SP - Brazil
[3] Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N, Allee Geoffroy St Hilaire, F-33615 Pessac - France
[4] Inst Astrophys Paris, Paris - France
[5] Observ Nacl, Rua Gen Jose Cristino 77, BR-20921400 Rio De Janeiro - Brazil
[6] GMTO Corp, 465 N Halstead St, Suite 250, Pasadena, CA 91107 - USA
[7] Rubin Observ Project Off, 950 N Cherry Ave, Tucson, AZ 85719 - USA
[8] Univ Fed Santa Catarina, Dept Fis, BR-88040900 Florianopolis, SC - Brazil
Total Affiliations: 8
|
| Document type: | Journal article |
| Source: | ASTRONOMICAL JOURNAL; v. 161, n. 3 MAR 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
An exotic environment surrounds the young stellar groups associated with the Canis Major (CMa) OB1/R1 region, which probably was formed under feedback from at least three supernova events having occurred a few million years ago. We use astrometric data from the Gaia-DR2 to confirm the membership of the stars in CMa R1, based on proper motion and parallax, which revealed 514 new members and candidates. The mean age of 5 Myr estimated from the color-magnitude diagram characterizes the sources as likely pre-main-sequence candidates. In total, a sample of 694 stars detected with the T80-South telescope was analyzed according to different color-color diagrams, which were compared with theoretical colors from evolutionary models, aiming to reveal the objects that exhibit color excess due to accretion processes. Accretion and magnetic activity were also explored on the basis of empirical flux-flux relation, such as F-660 and F-861 that are related to H alpha and Ca ii triplet emission, respectively. A low fraction (similar to 3 percent) of the sample have H alpha excess and other colors expected for stars exhibiting chromospheric activity. The number of Class I and Class II objects, identified by the infrared (Wide-field Infrared Survey Explorer) colors, indicates a disk fraction of similar to 6 percent, which is lower than that expected for stellar clusters with a similar age. Such a large sample of objects associated with CMa R1 without evidences of circumstellar accretion can be interpreted as a lack of disk-bearing stars, unusual for young star-forming regions. However, this may be explained as the result of supernova events. (AU) | |
| FAPESP's process: | 18/06822-6 - Multi-band study of protostellar objects in the star forming region CMa R1 |
| Grantee: | Thais dos Santos Silva |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 14/18100-4 - Stellar populations in the Milky Way: bulge, halo, disk and star forming regions; instrumentation for high resolution spectroscopy |
| Grantee: | Beatriz Leonor Silveira Barbuy |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 18/21250-9 - Identification of bright ultra-metal-poor stars from Multi-Band photometry and spectroscopic follow-up |
| Grantee: | Hélio Dotto Perottoni |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 17/19458-8 - Use of fractal statistics in the search for structural parameters in clusters of young stars |
| Grantee: | Annibal Hetem Junior |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 17/18191-8 - High-mass star formation: the mass of the central sources and the physics of the accretion process |
| Grantee: | Felipe Donizeti Teston Navarete |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 18/05866-0 - XXXth IAU General Assembly of the International Astronomical Union |
| Grantee: | Jane Cristina Gregorio-Hetem |
| Support Opportunities: | Research Grants - Meeting - Abroad |