X-ray Data Analysis Workshop

Group 2 (NCU)

Homework Contents

• Download Chandra data, extract the lightcurve and spectrum.

• Identify spectral lines.

• Make a true color image using three idetified elements.

• Compare Swift with Chandra data.

• Cas A:111.7-02.1, W 81, SN 1680– A young supernova remnant (extended source)– Exploded more than 300 years ago– Distance: ~10,000 ly– Gas shell diameter: 10 ly

• Chadra data summary– Obsid:114– Observed date: 2000/01/30/10:40:42UT– Detector: ACIS-S– Grating: None– Exposure time: 50,560 sec– File size: 512 Mb

#Chose the data after confirm the exposure time, or you’ll wait for a long~long time….

Light curveds9 --- make source region and background region

CIAO --- extract light curve

dmextract /infile="acisf00114N003_evt2.fits[sky=region(source.reg)][bin time=::4.0]" outfile="lightcurve.fits" opt="ltc1"

fplot --- plot light curve

Light curve of Cas A

Extract Spectrum

Identification of Spectral LinesElement Energy(keV)

O 0.547

O 0.654

Ne 0.922

Ne 1.022

Si 1.865

Si 2.006

S 2.461

S 2.632

Ref: http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/students-worksheet-id.html

True Color Image

True color image was made using Funtools.

Ne : Red (1.04-1.21 keV)

Si : Blue (1.64-2.15 keV)

S : Green (2.30-2.63 keV)

True Color Chandra Image of Cas A

Compare Swift with Chandra data

http://www.nasa.gov/mission_pages/chandra/main/index.html

http://www.nasa.gov/mission_pages/swift/main/index.html

Compare of Image

Swift Chandra

Pulsar

Different angular resolution (Swift 15 arc-sec, Chandra <0.5 arc-sec)

Compare of true color image

Swift Chandra

Compare of spectrum

Swift Chandra

Different exposure time (Swift: 4,990 sec, Chandra: 50,560sec)Noise??