| Title | The stellar spectral features of nearby galaxies in the near infrared: tracers of thermally pulsing asymptotic giant branch stars? |
| Authors | Riffel, Rogerio Mason, Rachel E. Martins, Lucimara P. Rodriguez-Ardila, Alberto Ho, Luis C. Riffel, Rogemar A. Lira, Paulina Gonzalez Martin, Omaira Ruschel-Dutra, Daniel Alonso-Herrero, Almudena Flohic, Helene McDermid, Richard M. Ramos Almeida, Cristina Thanjavur, Karun Winge, Claudia |
| Affiliation | Univ Fed Rio Grande do Sul, Dept Astron, Porto Alegre, RS, Brazil. Gemini Observ, Northern Operat Ctr, Hilo, HI 96720 USA. Univ Cruzeiro Sul, NAT, BR-01506000 Sao Paulo, SP, Brazil. Lab Nacl Astrofis, BR-37504364 Itajuba, MG, Brazil. Peking Univ, Kavli Inst Astron & Astrophys, Beijing 100871, Peoples R China. Peking Univ, Sch Phys, Dept Astron, Beijing 100871, Peoples R China. Univ Fed Santa Maria, Dept Fis, CCNE, BR-97105900 Santa Maria, RS, Brazil. Univ Chile, Dept Astron, Santiago, Chile. Inst Astrofis Canarias, E-38205 Tenerife, Spain. Univ La Laguna, Dept Astrofis, E-38205 Tenerife, Spain. Univ Cantabria, CSIC, Inst Fis Cantabria, E-39005 Santander, Spain. Univ Pacific, Dept Phys, Stockton, CA 95211 USA. Australian Astron Observ, Epping, NSW 1710, Australia. Macquarie Univ, Dept Phys & Astron, N Ryde, NSW 2109, Australia. Univ Victoria, Dept Phys & Astron, Victoria, BC V8P 1A1, Canada. Gemini Observ, Southern Operat Ctr, AURA, La Serena, Chile. Univ Fed Rio Grande do Sul, Dept Astron, Ave Bento Goncalves 9500, Porto Alegre, RS, Brazil. |
| Keywords | stars: AGB and post-AGB galaxies: active galaxies: bulges galaxies: stellar content TP-AGB STARS POST-STARBURST GALAXIES ACTIVE GALACTIC NUCLEI HIGH-REDSHIFT GALAXIES DIGITAL SKY SURVEY POPULATION-MODELS GLOBULAR-CLUSTERS INTERMEDIATE-AGE ENERGY-DISTRIBUTIONS MAGELLANIC-CLOUD |
| Issue Date | 2015 |
| Publisher | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY |
| Citation | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY.2015,450,(3),3069-3079. |
| Abstract | We analyse the stellar absorption features in high signal-to-noise ratio (S/N) near-infrared (NIR) spectra of the nuclear region of 12 nearby galaxies, mostly spirals. The features detected in some or all of the galaxies in this sample are the TiO (0.843 and 0.886 mu m), VO (1.048 mu m), CN (1.1 and 1.4 mu m), H2O (1.4 and 1.9 mu m) and CO (1.6 and 2.3 mu m) bands. The C-2 (1.17 and 1.76 mu m) bands are generally weak or absent, although C-2 (1.76 mu m) may be weakly present in the mean galaxy spectrum. A deep feature near 0.93 mu m, likely caused by CN, TiO and/or ZrO, is also detected in all objects. Fitting a combination of stellar spectra to the mean spectrum shows that the absorption features are produced by evolved stars: cool giants and supergiant stars in the early- or thermally pulsing asymptotic giant branch (E-AGB or TP-AGB) phases. The high luminosity of TP-AGB stars, and the appearance of VO and ZrO features in the data, suggest that TP-AGB stars dominate these spectral features. However, a contribution from other evolved stars is also likely. Comparison with evolutionary population synthesis models shows that models based on empirical libraries that predict relatively strong NIR features provide a more accurate description of the data. However, none of the models tested accurately reproduces all of the features observed in the spectra. To do so, the models will need to not only improve the treatment of TP-AGB stars, but also include good quality spectra of red giant and E-AGB stars. The uninterrupted wavelength coverage, high S/N and quantity of features we present here will provide a benchmark for the next generation of models aiming to explain and predict the NIR properties of galaxies. |
| URI | http://hdl.handle.net/20.500.11897/418944 |
| ISSN | 0035-8711 |
| DOI | 10.1093/mnras/stv866 |
| Indexed | SCI(E) |
| Appears in Collections: | 科维理天文与天体物理研究所 物理学院 |
