NGC3603 和 MSX

1. NGC3603和MSX NGC3603的MSX数据处理

2. HistoryFailure  Failure? • ROSAT (X) 曝光修正 debian Xselect,ftools 数据自身问题，放弃. email (03冬.SF) • MSX (Mid-Infrared) segment error,wcs etc… 计算机图形学,fits格式.

3. 内容 MSX 1.简介 2.正常方法处理MSX数据遇到的问题 3.解决方法 NGC3603 1. 简介 2. 数据处理过程及遗留的问题 3. 拟和结果及遗留的问题 附录: PAH(略)及分子光谱学

4. MSX • Introduction The Midcourse Space Experiment (MSX) Galactic Plane Survey has mapped the Galactic Plane for |b| < 5 degrees, the 4% of the sky missed by IRAS (2 IRAS gaps), regions of high source density including 8 star forming regions (Kraemer et al. 2002) and 10 galaxies (Kraemer et al. 2002), and 13 solar system objects (12 comets and asteroids and the Moon) in six mid-infrared spectral bands using the SPIRIT III infrared telescope. An overview of the astronomical experiments conducted with MSX is given by Price (1995). A more complete description of the infrared experiments and data processing is given in Price et al. (2001). The SPIRIT III infrared telescope is a 33 cm clear aperture off-axis telescope with five line-scanned infrared focal plane arrays (Bands A, B, C, D and E) cooled by a solid hydrogen cryostat. The Si:As blocked impurity band focal plane arrays consisted of eight columns of 192 18.3x18.3 arcsecond detectors. Half of the columns for each detector band were offset by half a detector to provide critical sampling in the cross-scan direction. The detector arrays covered a 1 degree cross-scan field of view. The scan and sample rates provided 2-8 data samples per pixel (depending on number of active columns) for an individual scene (final image pixels are the average of 1-7 scene pixels for the Galactic Plane images, 4-36 for the higher sensitivity and out-of-plane images, 2-30 for the IRAS gap images with the coverage being highly location dependent). 

5. Introduction • The Midcourse Space Experiment (MSX) • The MSX satellite, launched on April 24, 1996, was five meters long and weighed 2,700 kg. It was inserted into a 900 km, polar, near-Sun synchronous orbit on a Delta II vehicle. The infrared sensors operated at 11 to 12 degrees Kelvin by employing a solid hydrogen cryostat. The IR instruments spanned the range 4.2 - 26 microns. The focal plane arrays included five radiometer bands with a beam-size 35 times smaller than IRAS, resulting in images with excellent spatial resolution. The cryogen phase of the mission ended on 26 February 1997. Over 200 Giga Bytes of data on Celestial Backgrounds were obtained during the ten month cryogen phase of the mission. See the MSX Celestial Backgrounds Team Home Page for additional details.

6. Mission Characteristics: • Lifetime:1996-1997Wavelength:A (8.28 µm); C (12.13 µm); D (14.65 µm); E (21.3 µm)Area Coverage:0 < l < 360, |b| < 5 ; IRAS gaps; select targetsInstruments: • SPIRIT III infrared telescope (33-cm aperture) • solid hydrogen-cooled five line-scanned infrared focal plane arraysScience Products:Survey images and source catalogs; deeper raster scans of selected star formation regions and galaxies; raster scans of the IRAS gaps

7. More • Survey coverage: 0 < l < 360, |b| < 5, 300 < l < 30, 5 < b < 6.5 Wavelength coverage: 4 bands (8.3, 12.1, 14.7, 21.3 microns)Image resolution: 20 arcseconds, 72 arcseconds (low res mosaics)Positional accuracy: 2 arcseconds rmsImage noise (rms): 1.9-4.8 10-7 W m-2 sr-1 (at 8.3 microns) 5.9-11.8 10-7 W m-2 sr-1 (at 12.1 microns) 3.6-8.9 10-7 W m-2 sr-1 (at 14.7 microns) 13.3-29.8 10-7 W m-2 sr-1 (at 21.3 microns) Each image is a Cartesian projection about the Galactic center in Galactic latitude and longitude. The image units are of in-band radiance (W m-2 sr-1). The 72 arcsecond images have rms noise levels six times lower than the corresponding 20 arcsecond images. These lower resolution images are intended for examination of large regions of the Galactic plane and comparison with radio surveys and other data of comparable resolution.

8. 飞船结构

9. SPRIT III 简图

10. SPIRIT III 精度

11. 其他测量 • UV • 地面形迹

12. Public links Catalog数据 • ftp://spider.ipac.caltech.edu/pub/irsa_ftp/catalogs/MSX/ Image server • http://irsa.ipac.caltech.edu/applications/MSX/MSX

13. Private links • http://spider.ipac.caltech.edu/staff/mmm/msx-related/msx-related.html

14. 问题 • Fv无法做probe • Wavdetect • Cfitsio • Ds9 (单向) • Others wcstools-3.5.2 wcslib-2.5

15. 跟踪 • Gdb source code • Strace binary (trace system call) • Ldd dynamic lib. Ltrace. 猜测共同点: “WCS库.” Search. 所有的wcs库都存在同样的问题.

16. Todo • Help desk image help desk -> team http://gibbs1.plh.af.mil/ n x email 无回复. dns failure now. • Write wcs lib • Write all • 放弃,换方向

17. WCS WCS(World Coordinate System ) The WCS conventions are currently described in a set of 4 papers. The first 3 papers have been approved by the IAU-FWG and are now officially recognized as part of the FITS Standard. • Representations of World Coordinates in FITS, Greisen, E. W., and Calabretta, M. R., Astronomy & Astrophysics, 395, 1061-1075, 2002. (PDF, HTML). (These links to the publisher's web site are currently available by subscription only). Reprints are available from the author's web site in PDF format. • Representations of celestial coordinates in FITS Calabretta, M. R., and Greisen, E. W., Astronomy & Astrophysics, 395, 1077-1122, 2002. (PDF, HTML). (These links to the publisher's web site are currently available by subscription only). Reprints are available from the author's web site in PDF format. • "Representations of spectral coordinates in FITS", Greisen, E. W., Calabretta, M. R., Valdes, F. G., and Allen, S. L., Astronomy & Astrophysics, (in press). The latest draft of this paper is available from the author's web site. • "Representaions of distortions in FITS world coordinate systems" by Calabretta, et al. The latest draft of this paper are available from the author's web site. A related proposal by Steve Allen and Doug Mink for concatenating WCS keywords eventually may be incorporated into the final version of 4th WCS paper.

18. Lucky • 可证MSX的坐标是简单的平面影射， 不需要复杂的5步投影. (略)

19. fits标准 http://fits.gsfc.nasa.gov/ 重要文档 • Version 2.1 - this is the latest version of the FITS Standard that reflects the changes that were approved by the FITS Working Group in April 2005. • FITS User's Guide - an out of date (April 1997) introduction to the history and usage of FITS. This document does not reflect the changes that were introduced in version 2.0 of the FITS Standard that was approved in the year 2000, nor does it address the FITS conventions that are defined in the series of World Coordinate System (WCS) papers that have been approved by the FITS Working Group. The User's guide is also available in PDF and postscript formats, as well as the LaTeX source text file and style file. Cfitsio. –带过来！

20. 编程 • Image (simple) • 借鉴cfitsio list.c 基本读写函数(像素坐标) p2g.c 像素坐标<->银道坐标转换

21. NGC3603简介 Where the Stars Are • Massive stars are gregarious from birth. The tend to form in tight groups called star clusters or OB associations. These massive stars forming regions are often called starbursts since the formation of these stars is so rapid and so violent. Such regions are rare in the Milky Way, though they act as agents of change in the Galaxy in a number of ways: strong winds from the massive stars blow out into the Galaxy and re-arrange the interstellar gas and dust; the high energy radiation from the stars heats the Galaxy; and finally these stars will explode as supernova, violently disrupting their neighborhoods (but maybe triggering another starburst somewhere else). The false-color image above is a Chandra X-ray image of NGC 3603, one of the regions of the Milky Way where dozens of extremely massive stars were born in a burst of star formation about 2 million years ago. The dots in the picture represent X-ray bright stars, some of which are known massive stars, and many of which are as yet unidentified. The image shows the X-ray intensity, where green is faint, red is brighter, and blue-white is brightest. The number of X-ray stars increases dramatically near the center of NGC 3603 at the center of the image. The image above right shows a zoomed image of the central part of the cluster. The "white" star at the center is the brightest X-ray emitting object in the field is probably a binary in which the X-rays are produced when the powerful wind from one of the stars collides with the wind from the other in between the two stars. For comparison, the other X-ray bright "star" in the center to the right of the brightest object, is actually composed of the emission of 4 stars packed so tightly they appear as one to Chandra.

22. NGC3603 Chandra照片

23. Ngc3603 哈勃望远镜照片

24. ACDE

25. Data process • 去掉点源! • 去掉背景 • 得到流量-频率图

26. 去点源 方案1 : 通过catalog数据处理. (catalog是level3的数据). a: 寻找catalog处理软件 结果: twomass only b: 根据电源流量手动挖点源. 结果:CDE波段质量标记为无效.

27. 去点源 • 方案2,使用挖点源的工具从fits文件直接挖. • IRAF 只能一个一个的挖.

28. 挖点源 • 方案3 programming: 自己挖 PSF? 二维小波?

29. 计算机图形学 • 边缘检测和连接: Sobel laplace robert 算子 • 局域二值化方法 • 形态学开运算 2xbook 折中: Sobel算子检测. “碰撞扩散”(me)法连接.

30. 原文件

31. 挖掉电源和恒星形成区的结果

32. 拟和 • 黑体谱 double f(double V,double u,double T) { return (V*u*u*u / (exp(50*u/T)-1)); } /* goodness function */ double DF(double V,double T) { return( (pow(f(V,ua,T)-fa,2)/ea +pow(f(V,uc,T)-fc,2)/ec //+pow(f(V,ud,T)-fd,2)/fd +pow(f(V,ue,T)-fe,2)/ee )/(3-2) ); }

33. X^2检验 X^2 = Sum( (yi-fi)^2 * xigmai -2 ) 应该接近自由度 N-m.其中fi为拟和值,为测量值. • N = x,y对的个数(测量组数目) • m = 待定参数个数->拟和方程的参数; 除去D波段,N=3,而参数方程为 y= V * x^3 /(exp (50 *x/T) - 1) 即两个参数V,T,所以m = 2. 所以自由度 = N-m = 3-2 = 1

34. 背景取5度的image(数据区2度)

35. 拟和结果

36. 挖点源中遗留的问题 • 背景对x^2的影响. X^2值很低(0.11)，努力调整中.

37. 误差计算中遗留的问题 • sqrt(f^2+bg^2)*相对误差. 这里f,bg是多个pixels的总合. 什么是平均相对误差? 平均每个pixels?

38. 对结果的解释 D 波段发生了什么的吸收？ • PAH • 烷烃 • 更多寻找中

39. PAH

40. PAH

42. 化学

47. 谢谢！