تقرير
iPTF16fnl: a faint and fast tidal disruption event in an E+A galaxy
| العنوان: | iPTF16fnl: a faint and fast tidal disruption event in an E+A galaxy |
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| المؤلفون: | Blagorodnova, N., Gezari, S., Hung, T., Kulkarni, S. R., Cenko, S. B., Pasham, D. R., Yan, L., Arcavi, I., Ben-Ami, S., Bue, B. D., Cantwell, T., Cao, Y., Castro-Tirado, A. J., Fender, R., Fremling, C., Gal-Yam, A., Ho, A. Y. Q., Horesh, A., Hosseinzadeh, G., Kasliwal, M. M., Kong, A. K. H., Laher, R. R., Leloudas, G., Lunnan, R., Masci, F. J., Mooley, K., Neill, J. D., Nugent, P., Powell, M., Valeev, A. F., Vreeswijk, P. M., Walters, R., Wozniak, P. |
| سنة النشر: | 2017 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - High Energy Astrophysical Phenomena |
| الوصف: | We present ground-based and \textit{Swift} observations of iPTF16fnl, a likely tidal disruption event (TDE) discovered by the intermediate Palomar Transient Factory (iPTF) survey at 66.6 Mpc. The lightcurve of the object peaked at absolute $M_g=-17.2$ mag. The maximum bolometric luminosity (from optical and UV) was $L_p~\simeq~(1.0\,\pm\,0.15) \times 10^{43}$ erg/s, an order of magnitude fainter than any other optical TDE discovered so far. The luminosity in the first 60 days is consistent with an exponential decay, with $L \propto e^{-(t-t_0)/\tau}$, where $t_0$=~57631.0 (MJD) and $\tau\simeq 15$ days. The X-ray shows a marginal detection at $L_X=2.4^{1.9}_{-1.1}\times 10^{39}$ erg/s (\textit{Swift} X-ray Telescope). No radio counterpart was detected down to 3$\sigma$, providing upper limits for monochromatic radio luminosity of $\nu L_{\nu} < 2.3\times10^{36}$ erg/s and $\nu L_{\nu}<1.7\times 10^{37}$ erg/s (VLA, 6.1 and 22 GHz). The blackbody temperature, obtained from combined \textit{Swift} UV and optical photometry, shows a constant value of 19,000 K. The transient spectrum at peak is characterized by broad He II and H$\alpha$ emission lines, with an FWHM of about 14,000 km/s and 10,000 km/s respectively. He I lines are also detected at $\lambda\lambda$ 5875 and 6678. The spectrum of the host is dominated by strong Balmer absorption lines, which are consistent with a post-starburst (E+A) galaxy with an age of $\sim$650 Myr and solar metallicity. The characteristics of iPTF16fnl make it an outlier on both luminosity and decay timescales, as compared to other optically selected TDEs. The discovery of such a faint optical event suggests a higher rate of tidal disruptions, as low luminosity events may have gone unnoticed in previous searches. Comment: 14 pages, 11 figures, accepted for publication in ApJ |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.3847/1538-4357/aa7579 |
| URL الوصول: | http://arxiv.org/abs/1703.00965 |
| رقم الأكسشن: | edsarx.1703.00965 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.3847/1538-4357/aa7579 |
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