The Nature of the Compact Supernova Remnants in Starburst Galaxies

Chevalier, Roger A.; Fransson, Claes

doi:10.1086/323569

Cited by 75 publications

(107 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The larger velocities above are much higher (by a factor of 3−22) than the predicted velocities from the model of Chevalier & Fransson (2001), based on the high pressure expected in the interstellar medium (ISM) of M 82. The expansion velocity reported in this paper for SN2008iz is indeed a factor ∼40 larger than the predicted velocities in Chevalier & Fransson (2001), although of the same order-of-magnitude than the velocities reported in Beswick et al (2006) for the other remnants in M 82, and the typical velocities of the other type II supernovae observed to date. Weiler et al (1998) find a correlation between peak radio luminosity at 5 GHz and the time between the explosion and the peak in the 5 GHz light curve for type II supernovae.…”

Section: Comparison With Other Type II Radio Supernovaementioning

confidence: 70%

“…Estimates of the expansion velocities of other supernova remnants in M 82 (the host galaxy of SN 2008iz) have also been reported to range between ∼1500 and 11 000 km s −1 (Beswick et al 2006). The larger velocities above are much higher (by a factor of 3−22) than the predicted velocities from the model of Chevalier & Fransson (2001), based on the high pressure expected in the interstellar medium (ISM) of M 82. The expansion velocity reported in this paper for SN2008iz is indeed a factor ∼40 larger than the predicted velocities in Chevalier & Fransson (2001), although of the same order-of-magnitude than the velocities reported in Beswick et al (2006) for the other remnants in M 82, and the typical velocities of the other type II supernovae observed to date.…”

Section: Comparison With Other Type II Radio Supernovaementioning

confidence: 91%

See 1 more Smart Citation

VLBI observations of SN 2008iz

Brunthaler¹,

Martí-Vidal²,

Menten³

et al. 2010

A&A

View full text Add to dashboard Cite

We present observations of the recently discovered supernova 2008iz in M 82 with the VLBI High Sensitivity Array at 22 GHz, the Very Large Array at frequencies of 1. 4, 4.8, 8.4, 22 and 43 GHz, and the Chandra X-ray observatory. The supernova was clearly detected in two VLBI images separated by 11 months. The source shows a ring-like morphology and expands with a velocity of ∼23 000 km s −1 . The most likely explosion date is in mid-February 2008. The measured expansion speed is a factor of ∼2 higher than expected under the assumption that synchrotron self-absorption dominates the light curve at the peak, indicating that this absorption mechanism may not be important for the radio emission. We find no evidence for an asymmetric explosion. The VLA spectrum shows a broken power law, indicating that the source was still optically thick at 1.4 GHz in April 2009. Finally, we report upper limits on the X-ray emission from SN 2008iz and a second radio transient recently discovered by MERLIN observations.

show abstract

Section: Comparison With Other Type II Radio Supernovaementioning

confidence: 70%

Section: Comparison With Other Type II Radio Supernovaementioning

confidence: 91%

VLBI observations of SN 2008iz

Brunthaler¹,

Martí-Vidal²,

Menten³

et al. 2010

A&A

View full text Add to dashboard Cite

show abstract

“…However, it seems difficult to understand how such a large number of supernovae could be "hidden" without giving raise to non-thermal radio emission especially in such a high density region (cf. Chevalier & Fransson 2001 The answer to this apparent contradiction is simple: the difficulty arises from the fact that a proper geometrical constraint is used here for the first time implying a fairly large ionisation parameter. Had we neglected the information on the spatial extent (or better said, the compactness) of the emission associated with C2, we would easily be able to reconcile the observations with a standard value of M up for any burst age.…”

Section: An "Old" Hidden Compact Cluster?mentioning

confidence: 98%

High spatial resolution mid-infrared spectroscopy of NGC 5253: The stellar content of the embedded super-star cluster

Martín-Hernández

Schaerer

Sauvage³

2004

A&A

View full text Add to dashboard Cite

Abstract. We present the N-band (8-13 µm) spectrum of the hidden compact radio super-star cluster in NGC 5253, C2, obtained with TIMMI2 on the ESO 3.6 m telescope. The spectrum is characterised by a rising continuum due to warm dust, a silicate absorption and a strong [S ] line at 10.5 µm. Weaker lines of [Ar ] at 9.0 µm and [Ne ] at 12.8 µm are also present.The continuum can be modelled by an optically thick emission from hot (T d = 253 ± 1 K) dust emission extinguished by a cold foreground dust screen and a silicate absorption feature with A sil = 0.73 ± 0.05 mag. We show how the spatial scale of the observations greatly determine the mid-IR appearance of NGC 5253 and the important implications that this has on the interpretation of line fluxes in terms of the properties (age, IMF, etc.) of the embedded cluster. We have modelled the observed line fluxes towards C2 using photoionisation models with the most recent spectral energy distributions available to describe the integrated properties of the stellar cluster. The detailed dependence of the mid-IR lines on parameters such as the cluster age, upper mass cutoff and power law index of the IMF, as well as the local abundance, the presence of internal dust and the density structure is largely discussed. Strong constraints on the geometry based on high spatial resolution observations at different wavelengths -near-IR (HST and Keck), mid-IR (TIMMI2) and radio (VLA) -allows us to restrain the ionisation parameters to values log U ≥ −0.5 dex. This constraint on U leads to two possible solutions for the age and upper mass cutoff of C2: 1) a young (<4 Myr) cluster with a "non-standard" IMF having a low upper mass cutoff M up < 50 M ; and 2) a cluster of ∼5−6 Myr with a standard high upper mass cutoff (M up ∼ 100 M ). A young age of <4 Myr would agree with the lack of supernovae signatures in C2 and in case of being confirmed, would be the first indication for a "non-standard", low upper mass cutoff of the IMF for an individual massive cluster. An older age of ∼5-6 Myr would imply that it is possible to "contain" and hide such a compact cluster for a longer time that what it is generally thought. Arguments in favour and against these two scenarios are presented.The origin of the [O ] 25.9 µm emission measured by ISO and the possible presence of an intermediate mass black hole inside C2 are also addressed.

show abstract

“…(see e.g. Chevalier & Fransson 2001). There are also the star-forming molecular clouds Sgr A, Sgr B2 in the Galactic Center region with a strong CS emission from dense molecular gas (e.g.…”

Section: X-ray Emission From An Sn Fragment Interacting With a Molecumentioning

confidence: 99%

X-ray line emission from supernova ejecta fragments

Bykov

2002

A&A

View full text Add to dashboard Cite

Abstract. We show that fast moving isolated fragments of a supernova ejecta composed of heavy elements should be sources of K α X-ray line emission of the SN nuclear-processed products. Supersonic motion of the knots in the intercloud medium will result in a bow-shock/knot-shock structure creation. Fast nonthermal particles accelerated by Fermi mechanism in the MHD collisionless shocks diffuse through a cold metallic knot, suffering from Coulomb losses and producing the X-ray emission. We modeled the X-ray emission from a fast moving knot of mass M ∼ 10 −3 M , containing about ∼10 −4 M of any metal impurities like Si, S, Ar, Ca, Fe. The accelerated electron distribution was simulated using the kinetic description of charged particles interacting with a strong MHD shock. We accounted for nonlinear effects of shock modification by the nonthermal particle pressure. The K α line emission is most prominent for the knots propagating through dense molecular clouds. The bow shock should be a radiative wave with a prominent infrared and optical emission. In that case the X-ray line spectrum of an ejecta fragment is dominated by the low ionization states of the ions with the metal line luminosities reaching L x > ∼ 10 31 erg s −1 . High resolution XMM-Newton and Chandra observations are able to detect the K α and K β line emission from the knots at distances up to a few kpcs. The knots propagating through tenuous interstellar matter are of much fainter surface brightness but long-lived. The line spectra with higher ionization states of the ions are expected in that case. Compact dense knots could be opaque for some X-ray lines and that is important for their abundances interpretation. The ensemble of unresolved knots of galactic supernovae can contribute substantially to the iron line emission observed from the Galactic Center region and the Galactic ridge.

show abstract

The Nature of the Compact Supernova Remnants in Starburst Galaxies

Cited by 75 publications

References 35 publications

VLBI observations of SN 2008iz

VLBI observations of SN 2008iz

High spatial resolution mid-infrared spectroscopy of NGC 5253: The stellar content of the embedded super-star cluster

X-ray line emission from supernova ejecta fragments

Contact Info

Product

Resources

About