Research on stellar explosions at FINCA and Tuorla Observatory

Supernovae (SNe) are among the most energetic phenomena in the Universe. Core-collapse SNe mark the end-point in the evolution of massive stars, producing neutron stars, stellar mass black holes, and in exceptional cases, also long-duration gamma-ray bursts (GRBs). These explosions play a vital role in our understanding of stellar evolution, the synthesis of heavy elements, and through feedback processes also in galaxy evolution. Furthermore, as core-collapse SNe come from massive short-lived stars, their explosion rate directly reflects the on-going rate of star formation in their host galaxies, and thus they can also be used as probes of the cosmic star formation history which is one of the most fundamental observables in astrophysical cosmology.

The main research interests of the group focus on observational work on core-collapse SNe and range from detailed studies of individual SNe and their progenitor stars to the use of SNe as probes of their host galaxies, extinction and star formation rates. We are also interested in theoretical modelling of GRB prompt emission as well as their afterglow properties. The group has a strong interest in the occurrence of SNe within the nuclear regions of galaxies. In particular, we have been working on high spatial resolution searches and studies of SNe within the nuclear regions of luminous infrared galaxies (LIRGs). The group has also interest in detailed studies of star formation properties of LIRGs which are the most prolific SN factories and dominate the massive star formation (and thus also core-collapse SN rates) at redshifts between ~1 and ~2. We make use of observations at a wide range of wavelengths from radio, optical and infrared to X-rays. For this we use ground-based telescopes, e.g., the Very Large Telescope (VLT) of ESO and the Nordic Optical Telescope (NOT) as well as data from space telescopes such as the ESA Gaia, NASA Spitzer and ESA/NASA Hubble space telescopes and the NASA Chandra X-ray Observatory.

Recent papers:

Kankare et al. A&A in press: SN 2005at - A neglected type Ic supernova at 10 Mpc
Pennanen et al. 2014, A&A: Simulations of gamma-ray burst afterglows with a relativistic kinetic code
Kankare et al. 2014, MNRAS: The nature of supernovae 2010O and 2010P in Arp 299 - I. Near-infrared and optical evolution
Romero-Cañizales et al. 2014, MNRAS: The nature of supernovae 2010O and 2010P in Arp 299 - II. Radio emission
Kangas et al. 2013, MNRAS: Spatial distributions of core-collapse supernovae in infrared-bright galaxies
Mattila et al. 2013, MNRAS: Supernovae and radio transients in M82
Nicholl et al. (incl. Mattila, Kangas) 2013, Nature: Slowly fading super-luminous SNe that are not pair-instability explosions
Mattila et al. 2012, ApJ: Core-collapse Supernovae Missed by Optical Surveys
Kankare et al. 2012, MNRAS: SN 2009kn - the twin of the Type IIn supernova 1994W
Kankare et al. 2012, ApJ: Discovery of Two Supernovae in the Nuclear Regions of the Luminous Infrared Galaxy IC 883
Romero-Cañizales et al. 2012, A&A: e-MERLIN and VLBI observations of the luminous infrared galaxy IC 883
Grebenev et al. (incl. Tsygankov) 2012, Nature: Hard-X-ray emission lines from the decay of 44Ti in the remnant of SN 1987A
Vurm et al. (incl. Poutanen) 2011, ApJ: Gamma-ray bursts from magnetized collisionally-heated jets

M.Sc. and Ph.D. Theses on supernovae and gamma-ray bursts:

Erkki Kankare, PhD 2013: Supernovae in dense and dusty environments
Indrek Vurm, PhD 2010: Time-dependent modeling of radiative processes in
magnetized astrophysical plasmas
Jussi Harmanen, MSc 2014: SN 2011ap kehitys lähiultravioletista infrapunaan
Tuomas Kangas, MSc 2012: Supernovien populaatio ja edeltäjätähdet starburst
Venkatessh Ramakrishnan, MSc 2011: Detection of radio supernovae with the VLA

International projects offering possibilities for MSc and PhD projects:

Supernovae in Luminous Infrared Galaxies
Public ESO Spectroscopic Survey of Transient Objects (PESSTO)

For more information see recent talks in international meetings:

"Supernovae in nuclear environments", The fifth Gaia Science Alerts workshop,
Warsaw, 9/2014
"Adaptive Optics-assisted detection and study of supernovae", Shaping E-ELT
Science and instrumentation
, Ismanining, 2/2013

Contact: sepmat AT
Group members: