Issue |
A&A
Volume 422, Number 2, August I 2004
|
|
---|---|---|
Page(s) | 591 - 602 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361:20047001 | |
Published online | 09 July 2004 |
Dust-to-gas ratios in the Kepler supernova remnant
1
Instituto de Astronomia, Geofísica e Ciências Atmosféricas – USP, Brazil
2
School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel e-mail: contini@post.tau.ac.il
Received:
2
January
2004
Accepted:
31
March
2004
A new method to evaluate the dust-to-gas ratios in the Kepler SNR
is presented. Dust emission in the infrared and bremsstrahlung
are calculated consistently, considering that dust grains are collisionally
heated by the gas throughout the front and downstream of both the expanding and the reverse shocks.
The calculated continuum SED is constrained by the observational data.
The dust-to-gas ratios are determined by the ratio of the dust emission bump and
bremsstrahlung in the infrared.
The shell-like morphological similarity of X-ray and radio emission, and of
images in Hα and in infrared wavelengths
confirms that both radio and X-ray emissions are created at the front of the expanding shock
and that dust and gas are coupled crossing the expanding and reverse shock fronts.
The results show that large grains with radius of ~1 μm with dust-to-gas ratios <4 10-3 survive sputtering and are heated to a maximum temperature of 125 K
downstream of the shock expanding outwards with a velocity of about 1000
.
The high velocity shocks become radiative for dust-to-gas ratios >10-3.
Such shocks do not appear in the NE region, indicating that dust grains
are not homogeneously distributed throughout the remnant.
Smaller grains with radius of about 0.2 μm and dust-to-gas ratios
of ~4
10-4 are heated to a maximum temperature of ~50 K
downstream of the reverse shock corresponding to velocities of about 50
.
A maximum dust mass <0.16
is calculated.
Key words: ISM: supernova remnants / X-rays: stars / shock waves / ISM: individual objects: Kepler SNR
© ESO, 2004
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.