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Last modified: 6 October 2010


Sherpa References

Various Sherpa-related documents are available for download. Some are in HTML format, so they can be viewed directly in your web browser. Others are in PDF and Postscript format, so you must print them or examine them in an external viewer (such as Acrobat Reader or Ghostview).

Manuals | Presentations | Documents | Publications || Citing Sherpa in a Publication









The publication titles are linked to the article entry in the SAO/NASA Astrophysics Data System.


Systemization and Use of Atomic Data for Astrophysical Modeling
Brickhouse, Nancy S.
1999, ADASS VIII, ASPC, 172, 25
Extending and Enhancing the Capabilities of the Sherpa Modeling and Fitting Tool with S-Lang
Burke, D. J.; Siemiginowska, A.; Doe, S.; Nguyen, D.
2005, ADASS XIV, ASPC, 347, 105
The ASC Fitting Environment
Doe, S.; Conroy, M.; McDowell, J.
1996, ADASS V, ASPC, 101, 155
Extending Sherpa Data Analysis with S-Lang
Doe, S.; Freeman, P.; Smith, R.; Burke, D.; Siemiginowska, A.
2004, ADASS XIII, ASPC, 314, 404
Fitting and Modeling of AXAF Data with the ASC Fitting Application
Doe, S.; Ljungberg, M.; Siemiginowska, A.; Joye, W.
1998, ADASS VII, ASPC, 145, 157
Sherpa: Goals and Design for Chandra and Beyond
Doe, S., et al.
2006, ADASS XV, ASPC, 351, 77
Developing Sherpa with Python
Doe, S., et al.
2007, ADASS XVI, ASPC, 376, 543
Fitting and Modeling in the ASC Data Analysis Environment
Doe, S.; Siemiginowska, A.; Joye, W.; McDowell, J.
1997, ADASS VI, ASPC, 125, 492
Sherpa: a mission-independent data analysis application
Freeman, Peter; Doe, Stephen; Siemiginowska, Aneta
Proc. SPIE Vol. 4477
New Elements of Sherpa, CIAO's Modeling and Fitting Tool
Freeman, P. E.; Doe, S.; Siemiginowska, A.
2001, ADASS X, ASPC, 238, 483
Optimizing Functions Using ASCFIT
Grumm, David
1999, ADASS VIII, ASPC, 172, 365
CIAO 4 Preview: Sherpa and ChIPS Demo
Refsdal, B., et al.
2007, ADASS XVI, ASPC, 376, 711
AXAF Data Analysis Challenges
Siemiginowska, A.; Elvis, M.; Connors, A.; Freeman, P.; Kashyap, V.; Feigelson, E.
Statistical Challenges in Modern Astronomy II, 1997 (PS)



Statistical Challenges in Astronomy (
Feigelson, Eric D.; Babu, G. Jogesh
Springer-Verlag, 2003

Parameter Estimation and Model Comparison

Energy Spectra of X-ray Clusters of Galaxies
Avni, Y.
1976, ApJ, 210, 642
Parameter Estimation in Astronomy through Application of the Likelihood Ratio
Cash, W.
1979, ApJ, 228, 939
Generation of Confidence Intervals for Model Parameters in X-ray Astronomy
Cash, W.
1976, A&A, 52, 307
Parameter Estimation in X-ray Astronomy
Lampton, M.; Margon, B.; Bowyer, S.
1976, ApJ, 208, 177
Analyzing Gamma-ray Burst Spectral Data
Loredo, Thomas J.; Epstein, Richard I.
1989, ApJ, 336, 896
Chi-squared and C Statistic Minimization for Low Count per Bin Data
Nousek, John A.; Shue, David R.
1989, ApJ, 342, 1207
Statistics, Handle with Care: Detecting Multiple Model Components with the Likelihood Ratio Test
Protassov, Rostislav; van Dyk, David A.; Connors, Alanna; Kashyap, Vinay L.; Siemiginowska, Aneta
2002, ApJ, 571, 545
Parameter Estimation in X-ray Astronomy using Maximum Likelihood
Wachter, K.; Leach, R.; Kellogg, E.
1979, ApJ, 230, 274

X-ray Spectra and Detectors

The Formal Underpinnings of the Response Functions used in X-Ray Spectral Analysis
Davis, John E.
2001, ApJ, 548, 1010
The Analysis of X-ray Spectra
Gorenstein, P.; Gursky, H.; Garmire, G.
1968, ApJ, 153, 885
The Direct Deconvolution of X-ray Spectra
Kahn, S. M.; Blissett, R. J.
1980, ApJ, 238, 417

Citing Sherpa in a Publication

If you are writing a paper and would like to cite Sherpa, we recommend the following:

Sherpa: a mission-independent data analysis application (ADS)
P. E. Freeman, S. Doe, A. Siemiginowska
SPIE Proceedings, Vol. 4477, p.76, 2001

\bibitem[Freeman et al.(2001)]{2001SPIE.4477...76F} Freeman, P., Doe, S., 
\& Siemiginowska, A.\ 2001, \procspie, 4477, 76

The specific version of CIAO and CALDB (if applicable) used for the analysis should be mentioned as well.

A reference for the Python interface to Sherpa is also available:

Developing Sherpa with Python (ADS)
S. Doe, et al.
2007, ADASS XVI, 376, 543

\bibitem[Doe et al.(2007)]{2007ASPC..376..543D} Doe, S., et al.\ 2007, 
ADASS XVI, 376, 543

Further guidelines are available from the Acknowledgment of Use of Chandra Resources.

Last modified: 6 October 2010
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