تقرير
Star-formation histories of local luminous infrared galaxies
| العنوان: | Star-formation histories of local luminous infrared galaxies |
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| المؤلفون: | Pereira-Santaella, Miguel, Alonso-Herrero, Almudena, Colina, Luis, Miralles-Caballero, Daniel, Pérez-González, Pablo G., Arribas, Santiago, Bellocchi, Enrica, Cazzoli, Sara, Díaz-Santos, Tanio, López, Javier Piqueras |
| المصدر: | A&A 577, A78 (2015) |
| سنة النشر: | 2015 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | We present the analysis of the integrated spectral energy distribution (SED) from the ultraviolet (UV) to the far-infrared and H$\alpha$ of a sample of 29 local systems and individual galaxies with infrared (IR) luminosities between 10^11 Lsun and 10^11.8 Lsun. We have combined new narrow-band H$\alpha$+[NII] and broad-band g, r optical imaging taken with the Nordic Optical Telescope (NOT), with archival GALEX, 2MASS, Spitzer, and Herschel data. The SEDs (photometry and integrated H$\alpha$ flux) have been fitted with a modified version of the MAGPHYS code using stellar population synthesis models for the UV-near-IR range and thermal emission models for the IR emission taking into account the energy balance between the absorbed and re-emitted radiation. From the SED fits we derive the star-formation histories (SFH) of these galaxies. For nearly half of them the star-formation rate appears to be approximately constant during the last few Gyrs. In the other half, the current star-formation rate seems to be enhanced by a factor of 3-20 with respect to that occured ~1 Gyr ago. Objects with constant SFH tend to be more massive than starbursts and they are compatible with the expected properties of a main-sequence (M-S) galaxy. Likewise, the derived SFHs show that all our objects were M-S galaxies ~1 Gyr ago with stellar masses between 10^10.1 and 10^11.5 Msun. We also derived from our fits the average extinction (A_v=0.6-3 mag) and the polycyclic aromatic hydrocarbons (PAH) luminosity to L(IR) ratio (0.03-0.16). We combined the A_v with the total IR and H$\alpha$ luminosities into a diagram which can be used to identify objects with rapidly changing (increasing or decreasing) SFR during the last 100 Myr. Comment: 16 pages + online material, accepted for publication in A&A |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1051/0004-6361/201425359 |
| URL الوصول: | http://arxiv.org/abs/1502.07965 |
| رقم الأكسشن: | edsarx.1502.07965 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1051/0004-6361/201425359 |
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