Untangling the Remains of Cassiopeia A

Nustar_nustar140219a_500

nustar_nustar140219a February 19th, 2014

Credit: NASA/JPL-Caltech/CXC/SAO

The mystery of how Cassiopeia A exploded is unraveling thanks to new data from NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR. In this image, NuSTAR data, which show high-energy X-rays from radioactive material, are colored blue. Lower-energy X-rays from non-radioactive material, imaged previously with NASA's Chandra X-ray Observatory, are shown in red, yellow and green.

The new view shows a more complete picture of Cassiopeia A, the remains of a star that blew up in a supernova event whose light reached Earth about 350 years ago, when it could have appeared to observers as a star that suddenly brightened. The remnant is located 11,000 light-years away from Earth.

NuSTAR is the first telescope capable of taking detailed pictures of the radioactive material in the Cassiopeia A supernova remnant. While other telescopes have detected radioactivity in these objects before, NuSTAR is the first capable of pinpointing the location of the radioactivity, creating maps. When massive star explode, they create many elements: non-radioactive ones like iron and calcium found in your blood and bones; and radioactive elements like titanium-44, the decay of which sends out high-energy X-ray light that NuSTAR can see.

By mapping titanium-44 in Cassiopeia A, astronomers get a direct look at what happened in the core of the star when it was blasted to smithereens. These NuSTAR data complement previous observations made by Chandra, which show elements, such as iron, that were heated by shock waves farther out from the remnant's center.

In this image, the red, yellow and green data were collected by Chandra at energies ranging from 1 to 7 kiloelectron volts (keV). The red color shows heated iron, and green represents heated silicon and magnesium. The yellow is what astronomers call continuum emission, and represents a range of X-ray energies.

The titanium-44, shown in blue, was detected by NuSTAR at energies ranging between 68 and 78 keV.

The NuSTAR observations point to a possible solution to the puzzle of how stars detonate. The fact that the titanium -- which is a direct tracer of the supernova blast -- is concentrated in clumps at the core supports a theory referred to as "mild asymmetries." In this scenario, material sloshes about at the heart of the supernova, reinvigorating a shock wave and allowing it to blow out the star's outer layers.

Image Source: /image/nustar/nustar140219a

Curator: NuSTAR: Nuclear Spectroscopic Telescope Array, Pasadena, CA

Image Use Policy: http://www.jpl.nasa.gov/imagepolicy/

Image Details

Image Type
Observation
Object Name
Cassiopeia A Cas A
Subject - Milky Way
Nebula » Type » Supernova Remnant

Distance

Universescale1
11,000 light years
Nustar_nustar140219a_128
 

Position Details

Position (ICRS)
RA = 23h 23m 25.9s
DEC = 58° 48’ 58.8”
Orientation
North is up
Field of View
8.3 x 8.3 arcminutes
Constellation
Cassiopeia

Color Mapping

  Telescope Spectral Band Wavelength
Arrow_left_blue NuSTAR X-ray (44Ti) 17.0 pm
Arrow_left_green Chandra X-ray (Si-Mg) 885.6 pm
Arrow_left_yellow Chandra X-ray (Continuum) 248.0 pm
Arrow_left_red Chandra X-ray (Fe) 187.9 pm
Green channel is a ratio of silicon and magnesium lines
Spectrum_xray1w
Arrow_top_blue
Arrow_top_green
Arrow_top_yellow
Arrow_top_red
Nustar_nustar140219a_1280
×
ID
nustar140219a
Subject Category
B.4.1.4  
Subject Name
Cassiopeia A, Cas A
Credits
NASA/JPL-Caltech/CXC/SAO
Lightyears
11,000
Redshift
Reference Url
/image/nustar/nustar140219a
Type
Observation
Image Quality
Good
Distance Notes
Facility
NuSTAR, Chandra, Chandra, Chandra
Instrument
Color Assignment
Blue, Green, Yellow, Red
Band
X-ray, X-ray, X-ray, X-ray
Bandpass
44Ti, Si-Mg, Continuum, Fe
Central Wavelength
0.016984, 0.8856, 0.24797, 0.18785
Start Time
Integration Time
Dataset ID
Notes
G
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
350.85792622609534, 58.816320863129
Reference Dimension
3000, 3000
Reference Pixel
1500, 1500
Scale
-4.6182337591048391E-05, 4.6182337591048391E-05
Rotation
0.0
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
NuSTAR: Nuclear Spectroscopic Telescope Array
URL
http://www.nustar.caltech.edu
Name
Email
Telephone
Address
City
Pasadena
State/Province
CA
Postal Code
Country
Rights
http://www.jpl.nasa.gov/imagepolicy/
Publisher
Publisher ID
nustar
Resource ID
Resource URL
/image/nustar/nustar140219a
Related Resources
Metadata Date
2014-07-16 17:33:09 -0700
Metadata Version
1.2
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Detailed color mapping information coming soon...

 

×
Universescalefull
11,000 light years