Related papers: Interstellar atoms, molecules and diffuse bands to…

We present new pre-maximum and late-time optical photometry of the Type Ia/IIn supernova 2002ic. These observations are combined with the published V-band magnitudes of Hamuy et al. (2003) and the VLT spectrophotometry of Wang et al. (2004)…

Context: Numerous studies of diffuse interstellar band (DIB) profiles have detected substructures, which in turn suggests that large molecules are acting as their carriers. However, some of the narrowest DIBs generally do not show such…

We present observations and interpretation of the Type IIn supernova SN 2008am discovered by the ROTSE Supernova Verification Project (RSVP). SN 2008am peaked at approximately -22.3 mag at a redshift of z=0.2338, giving it a peak luminosity…

H$_{\rm I}$ 21-cm and $^{12}$CO 2.6-mm line emissions respectively trace the atomic and molecular gas phases, but they miss most of the opaque H$_{\rm I}$ and diffuse H$_2$ present in the Dark Neutral Medium (DNM) at the transition between…

Massive galaxy clusters at intermediate redshift can magnify the flux of distant background sources by several magnitudes and we exploit this effect to search for lensed distant supernovae that may otherwise be too faint to be detected. A…

Most of the observational studies of supernova (SN) explosions are limited to early phases (< a few yr after the explosion) of extragalactic SNe and observations of SN remnants (> 100 yr) in our Galaxy or very nearby galaxies. SNe at the…

We present a detailed analysis of the extremely luminous Type IIn supernova SN2006gy using spectra obtained between days 36 and 237 after explosion. We derive the temporal evolution of the effective temperature, radius, expansion speeds,…

The spectrum of any star viewed through a sufficient quantity of diffuse interstellar material reveals a number of absorption features collectively called diffuse interstellar bands (DIBs). The first DIBs were reported 90 years ago, and…

Fluxes of the diffuse supernova neutrino background (DSNB) are calculated based on a new modeling of galactic chemical evolution, where a variable stellar initial mass function (IMF) depending on the galaxy type is introduced and black hole…

We are conducting a study on the imprint of the ISM on optical spectra based on two types of ongoing spectroscopic massive-star surveys: on the one hand, intermediate-resolution (R = 2500) green-blue spectra for ~3000 stars obtained with…

We present a theoretical interpretation of the broad silicon and iron UV absorption features observed with the Hubble Space Telescope in the spectrum of the Schweizer-Middleditch star behind the remnant of Supernova 1006. These features are…

This is the first in a series of three papers describing a project with the Cosmic Origins Spectrograph on the Hubble Space Telescope to measure abundances of the neutral interstellar medium (ISM) in a sample of 9 nearby star-forming…

We present optical and infrared photometry of the unusual Type Ia supernova 2000cx. With the data of Li et al. (2001) and Jha (2002), this comprises the largest dataset ever assembled for a Type Ia SN, more than 600 points in UBVRIJHK. We…

Diffuse interstellar bands (DIBs) are absorption features commonly observed in optical/near-infrared spectra of stars and thought to be associated with polyatomic molecules that comprise a significant reservoir of organic material in the…

We study the spectroscopic evolution of superluminous supernovae (SLSNe) later than 100 days after maximum light. We present new data for Gaia16apd and SN2017egm, and analyse these with a larger sample comprising 41 spectra of 12 events.…

We present near- and mid-infrared (IR) photometric data of the Type Ibn supernova (SN) 2006jc obtained with the United Kingdom Infrared Telescope (UKIRT), the Gemini North Telescope, and the Spitzer Space Telescope between days 86 and 493…

We present moderately-high resolution echelle observations of the nucleus of NGC 5195, the line of sight to which samples intervening interstellar material associated with the outer spiral arm of M51. Our spectra reveal absorption from…

We present equivalent width measurements and limits of six diffuse interstellar bands (DIBs) in seven damped Ly-alpha absorbers (DLAs) over the redshift range 0.091<z<0.524, sampling 20.3<log[N(HI)]<21.7. DIBs were detected in only one of…

We critically examine a scenario for the enrichment of the interstellar medium (ISM) in which supernova ejecta follow a long (10^8 yr) journey before falling back onto the galactic disk in the form of metal-rich ``droplets'', These droplets…

The coming era of large photometric wide-field surveys will increase the detection rate of supernovae by orders of magnitude. Such numbers will restrict spectroscopic follow-up in the vast majority of cases, and hence new methods based…