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

Manuals

The Chandra ABC Guide to Pileup (PS, 23 pages)
Scripting in CIAO webpages

Presentations

Sherpa

Sherpa: Modelling, Fitting, and Statistics - CIAO workshop, February 2010
Advanced Sherpa - CIAO workshop, February 2010
Scripting in CIAO - CIAO workshop, February 2010
Modeling, Fitting and Statistics - CIAO workshop, October 2008
The CIAO 4.0 Data Analysis System - HEAD meeting, 2008

Statistics

Statistics: Basic Concepts - Int'l X-ray Astronomy School, 2005
Statistics: Model Hypothesis Testing - Int'l X-ray Astronomy School, 2005
Statistics in the X-ray Regime - CIAO workshop, May 2002
Statistics I: Issues in Model Fitting in the X-ray Regime - GSFC X-ray School, 2001
Statistics II: Model Comparison and Parameter Estimation - GSFC X-ray School, 2001

Documents

Fitting

Spectral Fitting

Statistics

Statistics: a chapter for "X-ray Astronomy Handbook"

Publications

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

General

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)

Statistics

General

Statistical Challenges in Astronomy (amazon.com): 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.