scholarly journals Hubble Space TelescopeObservations of High‐Velocity Lyα and Hα Emission from Supernova Remnant 1987A: The Structure and Development of the Reverse Shock

2003 ◽  
Vol 593 (2) ◽  
pp. 809-830 ◽  
Author(s):  
Eli Michael ◽  
Richard McCray ◽  
Roger Chevalier ◽  
Alexei V. Filippenko ◽  
Peter Lundqvist ◽  
...  
Keyword(s):  
High Velocity ◽  
Supernova Remnant ◽  
Reverse Shock ◽  
Hα Emission ◽  
Supernova Remnant 1987A

scholarly journals A Key to Pulsar Wind Bubble Morphologies: Hydrodynamical Simulations

2004 ◽  
Vol 218 ◽  
pp. 175-178
Author(s):  
Eric van der Swaluw ◽  
Turlough P. Downes
Keyword(s):  
High Velocity ◽  
Supernova Remnant ◽  
Bow Shock ◽  
Shock Interaction ◽  
Reverse Shock ◽  
Supersonic Expansion ◽  
Expansion Stage ◽  
Pulsar Wind ◽  
Hydrodynamical Simulations

We present a model of a pulsar-driven supernova remnant, by using a hydrodynamics code, which simulates the evolution of a pulsar wind nebula when the pulsar is moving at a high velocity through its expanding supernova remnant. The simulation shows four different stages of the pulsar wind nebula: the supersonic expansion stage, the reverse shock interaction stage, the subsonic expansion stage and ultimately the bow shock stage. Due to the high velocity of the pulsar, the position of the pulsar is located at the head of the pulsar wind bubble, after the passage of the reverse shock. The resulting morphology of the pulsar wind bubble is therefore similar to the morphology of a bow shock pulsar wind nebulA. We show how to distinguish these two different stages, and apply this method to the SNR G327.1–1.1, for which we argue that there is no bow shock around its pulsar wind nebulA.

scholarly journals High-velocity gas associated with the supernova remnant S147

1981 ◽  
Vol 195 (3) ◽  
pp. 485-495 ◽  
Author(s):  
A. P. Phillips ◽  
P. M. Gondhalekar ◽  
J. C. Blades
Keyword(s):  
High Velocity ◽  
Supernova Remnant

scholarly journals Interaction of high-velocity pulsars with supernova remnant shells

2003 ◽  
Vol 397 (3) ◽  
pp. 913-920 ◽  
Author(s):  
E. van der Swaluw ◽  
A. Achterberg ◽  
Y. A. Gallant ◽  
T. P. Downes ◽  
R. Keppens
Keyword(s):  
High Velocity ◽  
Supernova Remnant

scholarly journals Detection of Hα Emission on High Velocity 21 cm Clouds

1990 ◽  
Vol 139 ◽  
pp. 193-198
Author(s):  
Guido Münch ◽  
Eckhart Pitz
Keyword(s):  
High Velocity ◽  
Galactic Latitude ◽  
Emission Rates ◽  
High Galactic Latitude ◽  
Continuum Intensity ◽  
Lyman Continuum ◽  
Local Standard ◽  
Direct Measurements ◽  
Hα Emission ◽  
Local Standard Of Rest

The measurement of Hα emission on two high galactic latitude clouds known to emit 21 cm lines with local standard of rest (LSR) velocities of −50 and −85 km s−1 is reported. The Hα lines have been found nearly at the velocities of the 21 CM features and have emission rates of 0.2 Rayleigh. The diffuse Lyman continuum intensity required to produce HI ionization at the measured rate is in agreement with the direct measurements made with the ultraviolet (UV) spectrometer of the Voyager 2 spacecraft.

scholarly journals High-Velocity Clouds and the Local Group

2004 ◽  
Vol 217 ◽  
pp. 2-11 ◽  
Author(s):  
B. P. Wakker
Keyword(s):  
High Velocity ◽  
Milky Way ◽  
Local Group ◽  
Current Data ◽  
The Other ◽  
Hot Gas ◽  
Neutral Gas ◽  
Hα Emission ◽  
M 31 ◽  
High Velocity Clouds

I examine some of the evidence relevant to the idea that high-velocity clouds (HVCs) are gas clouds distributed throughout the Local Group, as proposed by Blitz et al. (1999) and Braun & Burton (1999). This model makes several predictions: a) the clouds have low metallicities; b) there should be no detectable Hα emission; c) analogues near other galaxies should exist; and d) many faint HVCs in the region around M 31 can be found. Low metallicities are indeed found in several HVCs, although they are also expected in several other models. Hα emission detected in most HVCs and, when examined more closely, distant (D>200 kpc) HVCs should be almost fully ionized, implying that most HVCs with H I must lie near the Milky Way. No clear extragalactic analogues have been found, even though the current data appear sensitive enough. The final prediction (d) has not yet been tested. on balance there appears to be no strong evidence for neutral gas clouds distributed throughout the Local Group, but there may be many such clouds within 100 or so kpc from the Milky Way (and M31). on the other hand, some (but not all) of the high-velocity O VI recently discovered may originate in hot gas distributed throughout the Local Group.

scholarly journals High-velocity interstellar absorption associated with the supernova remnant W28

2020 ◽  
Vol 495 (3) ◽  
pp. 2909-2920 ◽  
Author(s):  
Adam M Ritchey
Keyword(s):  
High Velocity ◽  
Molecular Cloud ◽  
Supernova Remnant ◽  
Line Emission ◽  
Line Of Sight ◽  
Interstellar Gas ◽  
Lower Velocity ◽  
North East ◽  
The North ◽  
Visible Wavelengths

ABSTRACT We present an analysis of moderately high-resolution optical spectra obtained for the sightline to CD−23 13777, an O9 supergiant that probes high-velocity interstellar gas associated with the supernova remnant W28. Absorption components at both high positive and high negative velocity are seen in the interstellar Na i D and Ca ii H and K lines towards CD−23 13777. The high-velocity components exhibit low Na i/Ca ii ratios, suggesting efficient grain destruction by shock sputtering. High column densities of CH+, and high CH+/CH ratios, for the components seen at lower velocity may be indicative of enhanced turbulence in the clouds interacting with W28. The highest positive and negative velocities of the components seen in Na i and Ca ii absorption towards CD−23 13777 imply that the velocity of the blast wave associated with W28 is at least 150 km s−1, a value that is significantly higher than most previous estimates. The line of sight to CD−23 13777 passes very close to a well-known site of interaction between the supernova remnant and a molecular cloud to the north-east. The north-east molecular cloud exhibits broad molecular line emission, OH maser emission from numerous locations, and bright extended GeV and TeV γ-ray emission. The sightline to CD−23 13777 is thus a unique and valuable probe of the interaction between W28 and dense molecular gas in its environs. Future observations at ultraviolet and visible wavelengths will help to better constrain the abundances, kinematics, and physical conditions in the shocked and quiescent gas along this line of sight.

scholarly journals Deciphering the nature of the pulsar wind nebula CTB 87 with XMM–Newton

2019 ◽  
Vol 491 (2) ◽  
pp. 3013-3021 ◽  
Author(s):  
B Guest ◽  
S Safi-Harb ◽  
A MacMaster ◽  
R Kothes ◽  
B Olmi ◽  
...  
Keyword(s):  
Supernova Remnant ◽  
Thermal Emission ◽  
Plasma Temperature ◽  
Evolutionary Stage ◽  
Reverse Shock ◽  
X Ray ◽  
Upper Limit ◽  
Supernova Shell ◽  
Pulsar Wind ◽  
Hydrodynamical Simulations

ABSTRACT CTB 87 (G74.9+1.2) is an evolved supernova remnant (SNR) which hosts a peculiar pulsar wind nebula (PWN). The X-ray peak is offset from that observed in radio and lies towards the edge of the radio nebula. The putative pulsar, CXOU J201609.2+371110, was first resolved with Chandra and is surrounded by a compact and a more extended X-ray nebula. Here, we use a deep XMM–Newton observation to examine the morphology and evolutionary stage of the PWN and to search for thermal emission expected from a supernova shell or reverse shock interaction with supernova ejecta. We do not find evidence of thermal X-ray emission from the SNR and place an upper limit on the electron density of 0.05 cm−3 for a plasma temperature kT ∼ 0.8 keV. The morphology and spectral properties are consistent with a ∼20-kyr-old relic PWN expanding into a stellar wind-blown bubble. We also present the first X-ray spectral index map from the PWN and show that we can reproduce its morphology by means of 2D axisymmetric relativistic hydrodynamical simulations.

Evolution and Geometry of Hot Spots in Supernova Remnant 1987A

2002 ◽  
Vol 572 (1) ◽  
pp. 209-226 ◽  
Author(s):  
Ben E. K. Sugerman ◽  
Stephen S. Lawrence ◽  
Arlin P. S. Crotts ◽  
Patrice Bouchet ◽  
Steve R. Heathcote
Keyword(s):  
Hot Spots ◽  
Supernova Remnant ◽  
Supernova Remnant 1987A

The X‐Ray Spectrum of Supernova Remnant 1987A

2002 ◽  
Vol 574 (1) ◽  
pp. 166-178 ◽  
Author(s):  
Eli Michael ◽  
Svetozar Zhekov ◽  
Richard McCray ◽  
Una Hwang ◽  
David N. Burrows ◽  
...  
Keyword(s):  
Supernova Remnant ◽  
X Ray ◽  
Supernova Remnant 1987A
Sign in / Sign up

Export Citation Format

Share Document