English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Photometric and spectroscopic observations of a slowly declining, luminousType Ia supernova (SN Ia) SN 2011hr in the starburst galaxy NGC 2691 arepresented. SN 2011hr is found to peak at $M_{B}=-19.84 \pm 0.40\,\rm{mag}$,with a post-maximum decline rate $\Delta$m$_{15}$(B) = 0.92 $\pm$0.03\,$\rm{mag}$. From the maximum-light bolometric luminosity, $L=(2.30 \pm0.90) \times 10^{43}\,\rm{erg\,s^{-1}}$, we estimate the mass of synthesized\Nifs\ in SN 2011hr to be $M(\rm{^{56}Ni})=1.11 \pm 0.43\,M_{\sun}$. SN 2011hrappears more luminous than SN 1991T at around maximum light, and the absorptionfeatures from its intermediate-mass elements (IMEs) are noticeably weaker thanthe latter at similar phases. Spectral modeling suggests that SN 2011hr has theIMEs of $\sim$\,0.07 M$_{\sun}$ in the outer ejecta, which is much lower thanthe typical value of normal SNe Ia (i.e., 0.3 -- 0.4 M$_{\sun}$) and is alsolower than the value of SN 1991T (i.e., $\sim$\,0.18 M$_{\sun}$). These resultsindicate that SN 2011hr may arise from a Chandrasekhar-mass white dwarfprogenitor that experienced a more efficient burning process in the explosion.Nevertheless, it is still possible that SN 2011hr may serve as a transitionalobject connecting the SN 1991T-like SNe Ia with the superluminous subclass likeSN 2007if given that the latter also shows very weak IMEs at all phases.

A Luminous Peculiar Type Ia Supernova SN 2011hr: More Like SN 1991T or SN 2007if?