Multiwavelength evidence for_quasi_periodic_modulation_in_the_gamma_ray_blazar_pg_1553_113
A multiwavelength study of Cassiopeia A - NASA · Tracey DeLaney Subject: Chandra Year-4 Symposium...
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Shocked CSM: Forward Shock Material edge enhanced radio image "continuum" X-ray image "continuum" X-ray image The "continuum" X-ray emission is most likely forward shock material because it has similar spectra to the forward shock filaments. "low energy" X-ray image continuum-subtracted Hα image from Fesen 2001, ApJS, 133, 161 X-ray optical QSFs A Multiwavelength Study of Cassiopeia A Emphasizing the Separation Between Forward and Reverse Shock Material Tracey DeLaney (U. of MN), Lawrence Rudnick (U. of MN), Robert A. Fesen (Dartmouth), Una Hwang (NASA-GSFC, U. of MD), T. W. Jones (U. of MN), Robert Petre (NASA-GSFC), Jon A. Morse (ASU) Abstract We have performed a multiwavelength comparison of Cas A using VLA, HST, and CXO images. By separating components spectrally, we find clear associations between the emission at the three wavebands on scales of 10" to 1'. This breaks down at the 1" (.016 pc) level indicating that there is not microscopic mixing of the different temperature plasmas. We separate the emitting material into two components - shocked CSM and shocked ejecta, which show the same respective morphologies and proper motions in the different bands. In the shocked CSM, we find matched X-ray low-energy emission and optical QSFs, and X-ray continuum- dominated emission matched with filamentary radio structures. In the ejecta, as defined by X-ray and optical O, Si, and S line emission and flat-spectrum radio emission, there are large scale structures likely resulting from the explosion. There is also a great deal of material that is seen only in a single band; these show distinct kinematic structures as well. These different temperature components may represent varying density conditions and/or post-shock evolutionary states. Acknowledgements: This work was conducted at the University of Minnesota under Smithsonian grant Smithsonian/GO1- 2051A/NASA and HST grant HST-AR-09537.01 Spectral Component Separation Cas A is composed of many different components each with different spectral signatures. To understand the complex relationships in Cas A, we must separate the spectral structures and then compare the different wavebands. Otherwise, the task is nearly impossible. We construct a gallery of images from scaled subtractions of two input images: M t (A)=M 1 -AM 2 We then select the image that most represents the dominant behavior of the chosen spectral signature. Summary Emission Components in Cas A Type X-ray Optical Radio Nature Kinematics Ejecta strong lines FMKs flat spectrum dense 0.2-0.35 %/yr (Si) shocked ejecta CSM1 continuum -- filaments, edges diffuse 0.05-0.25 %/yr shocked CSM CSM2 enhanced QSFs -- dense -0.05-0.05 %/yr low energy shocked CSM Kinematic Analysis Proper motions measured for 261 X-ray knots and features The X-ray proper motions match those of clearly associated radio or optical features with published proper motions The histograms to the right show that there are also kinematically distinct singleband X-ray, optical, and radio features These singleband emitters may simply represent emission properties changing with time as features decelerate and/or change density Proper motion references: FMKs: Kamper & van den Bergh 1976, ApJS, 32, 351; QSFs: van den Bergh & Kamper 1985, ApJ, 293, 537 optical outlying knots: Thorstensen et al. 2001, AJ, 122, 297; radio: Anderson & Rudnick 1995, ApJ, 441, 307 0.3-10 keV Chandra X-ray Observatory image Epoch: 2000, Exposure: ACIS-S3 50 ks Hwang et al. 2000, ApJ, 537, L122 Hubble Space Telescope WFPC2 image Epoch: 2000, Filter: F675W Primary Lines: SII, OII, OI, NII, Hα Fesen et al. 2001, AJ, 122, 2644 6 cm Very Large Array image Epoch: 2000-2001 Configurations: ABCD red=radio green=optical blue=X-ray Broadband Images CSM2 CSM1 Shocked Ejecta: Reverse Shock Material 0.3-10 keV X-ray image "O" X-ray image "O" optical image "S" optical image "Si" X-ray image red="flat" radio blue="Si" X-ray FMKs
Transcript of A multiwavelength study of Cassiopeia A - NASA · Tracey DeLaney Subject: Chandra Year-4 Symposium...
Shocked CSM:Forward Shock Material
edge enhanced radio image
"continuum" X-ray image
"continuum" X-ray image
The "continuum" X-ray emission is most likely forward shock material because it has similar spectra to the forward shock filaments.
"low energy" X-ray image continuum-subtracted Hα imagefrom Fesen 2001, ApJS, 133, 161
X-ray
optical
QSFs
A Multiwavelength Study of Cassiopeia A Emphasizing the Separation Between Forward and Reverse Shock Material
Tracey DeLaney (U. of MN), Lawrence Rudnick (U. of MN), Robert A. Fesen (Dartmouth), Una Hwang (NASA-GSFC, U. of MD),
T. W. Jones (U. of MN), Robert Petre (NASA-GSFC), Jon A. Morse (ASU)
AbstractWe have performed a multiwavelength comparison of Cas A using VLA, HST, and CXO images. By separating components spectrally, we find clear associations between the emission at the three wavebands on scales of 10" to 1'. This breaks down at the 1" (.016 pc) level indicating that there is not microscopic mixing of the different temperature plasmas. We separate the emitting material into two components - shocked CSM and shocked ejecta, which show the same respective morphologies and proper motions in the different bands. In the shocked CSM, we find matched X-ray low-energy emission and optical QSFs, and X-ray continuum-dominated emission matched with filamentary radio structures. In the ejecta, as defined by X-ray and optical O, Si, and S line emission and flat-spectrum radio emission, there are large scale structures likely resulting from the explosion. There is also a great deal of material that is seen only in a single band; these show distinct kinematic structures as well. These different temperature components may represent varying density conditions and/or post-shock evolutionary states.
Acknowledgements: This work was conducted at the University of Minnesota under Smithsonian grant Smithsonian/GO1-2051A/NASA and HST grant HST-AR-09537.01
Spectral Component Separation
Cas A is composed of many different components each with different spectral signatures.
To understand the complex relationships in Cas A, we must separate the spectral structures and then compare the different wavebands. Otherwise, the task is nearly impossible.
We construct a gallery of images from scaled subtractions of two input images:
Mt(A)=M1-AM2
We then select the image that most represents the dominant behavior of the chosen spectral signature.
SummaryEmission Components in Cas A
Type X-ray Optical Radio Nature KinematicsEjecta strong lines FMKs flat spectrum dense 0.2-0.35 %/yr
(Si) shocked ejecta
CSM1 continuum -- filaments, edges diffuse 0.05-0.25 %/yrshocked CSM
CSM2 enhanced QSFs -- dense -0.05-0.05 %/yrlow energy shocked CSM
Kinematic AnalysisProper motions measured for 261 X-ray knots and features
The X-ray proper motions match those of clearly associated radio or optical features with published proper motions
The histograms to the right show that there are also kinematically distinct singleband X-ray, optical, and radio features
These singleband emitters may simply represent emission properties changing with time as features decelerate and/or change density
Proper motion references: FMKs: Kamper & van den Bergh 1976, ApJS, 32, 351; QSFs: van den Bergh & Kamper 1985, ApJ, 293, 537optical outlying knots: Thorstensen et al. 2001, AJ, 122, 297; radio: Anderson & Rudnick 1995, ApJ, 441, 307
0.3-10 keV Chandra X-ray Observatory imageEpoch: 2000, Exposure: ACIS-S3 50 ksHwang et al. 2000, ApJ, 537, L122
Hubble Space Telescope WFPC2 imageEpoch: 2000, Filter: F675WPrimary Lines: SII, OII, OI, NII, HαFesen et al. 2001, AJ, 122, 2644
6 cm Very Large Array imageEpoch: 2000-2001Configurations: ABCD
red=radiogreen=opticalblue=X-ray
Broadband Images
CSM2
CSM1
Shocked Ejecta: Reverse Shock Material
0.3-10 keV X-ray image
"O" X-ray image
"O" optical image
"S" optical image
"Si" X-rayimage
red="flat" radioblue="Si" X-ray
FMKs
