Massive stars exploding in a He-rich circumstellar medium - VII. The metamorphosis of ASASSN-15ed from a narrow line Type Ibn to a normal Type Ib Supernova

Autor: Pastorello, A., Prieto, J. L., Elias-Rosa, N., Bersier, D., Hosseinzadeh, G., Morales-Garoffolo, A., Noebauer, U. M., Taubenberger, S., Tomasella, L., Kochanek, C. S., Falco, E., Basu, U., Beacom, J. F., Benetti, S., Brimacombe, J., Cappellaro, E., Danilet, A. B., Dong, Subo, Fernandez, J. M., Goss, N., Granata, V., Harutyunyan, A., Holoien, T. W. -S., Ishida, E. E. O., Kiyota, S., Krannich, G., Nicholls, B., Ochner, P., Pojmanski, G., Shappee, B. J., Simonian, G. V., Stanek, K. Z., Starrfield, S., Szczygiel, D., Tartaglia, L., Terreran, G., Thompson, T. A., Turatto, M., Wagner, R. M., Wiethoff, W. S., Wilber, A., Wozniak, P. R.
Rok vydání: 2015
Předmět:
Zdroj: Monthly Notices of the Royal Astronomical Society 2015 453 (4): 3649-3661
Druh dokumentu: Working Paper
DOI: 10.1093/mnras/stv1812
Popis: We present the results of the spectroscopic and photometric monitoring campaign of ASASSN-15ed. The transient was discovered quite young by the All Sky Automated Survey for SuperNovae (ASAS-SN). Amateur astronomers allowed us to sample the photometric SN evolution around maximum light, which we estimate to have occurred on JD = 2457087.4 +- 0.6 in the r-band. Its apparent r-band magnitude at maximum was r = 16.91 +- 0.10, providing an absolute magnitude M(r) ~ -20.04 +- 0.20, which is slightly more luminous than the typical magnitudes estimated for Type Ibn SNe. The post-peak evolution was well monitored, and the decline rate (being in most bands around 0.1 mag/d during the first 25 d after maximum) is marginally slower than the average decline rates of SNe Ibn during the same time interval. The object was initially classified as a Type Ibn SN because early-time spectra were characterized by a blue continuum with superimposed narrow P-Cygni lines of He I, suggesting the presence of a slowly moving (1200-1500 km/s), He-rich circumstellar medium. Later on, broad P-Cygni He I lines became prominent. The inferred velocities, as measured from the minimum of the broad absorption components, were between 6000 and 7000 km/s. As we attribute these broad features to the SN ejecta, this is the first time we have observed the transition of a Type Ibn SN to a Type Ib SN.
Comment: 14 pages, 7 figures, 4 tables; published by MNRAS
Databáze: arXiv
Externí odkaz: