Abstract
Type Ia supernovae (SNe Ia) have been proposed to be much better
distance indicators at near-infrared (NIR) compared to optical
wavelengths - the effect of dust extinction is expected to be lower and
it has been shown that SNe Ia behave more like `standard candles' at NIR
wavelengths. To better understand the physical processes behind this
increased uniformity, we have studied the Y, J and H-filter light curves
of 91 SNe Ia from the literature. We show that the phases and
luminosities of the first maximum in the NIR light curves are extremely
uniform for our sample. The phase of the second maximum, the late-phase
NIR luminosity and the optical light-curve shape are found to be
strongly correlated, in particular more luminous SNe Ia reach the second
maximum in the NIR filters at a later phase compared to fainter objects.
We also find a strong correlation between the phase of the second
maximum and the epoch at which the SN enters the Lira law phase in its
optical colour curve (epochs ˜ 15 to 30 d after B-band maximum).
The decline rate after the second maximum is very uniform in all NIR
filters. We suggest that these observational parameters are linked to
the nickel and iron mass in the explosion, providing evidence that the
amount of nickel synthesized in the explosion is the dominating factor
shaping the optical and NIR appearance of SNe Ia.
Original language | English |
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Pages (from-to) | 1345-1359 |
Number of pages | 15 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 448 |
Issue number | 2 |
Early online date | 12 Feb 2015 |
DOIs | |
Publication status | Published - 01 Apr 2015 |
Externally published | Yes |
Keywords
- supernovae: general
- distance scale