1. Gerard Fitzpatrick Tutor: Andy Pollock Trainee Project 2009
The Ups & Downs of AB Dor
Gerard Fitzpatrick
Tutor: Andy Pollock
Trainee Project 2009
2009 Summer Alumni Trainee Meeting

2. Overview Introduction Middly Bit
Project
AB Dor
XMM (really brief)
Middly Bit
Data reduction & Analysis
XMMlccorr
Results
Conclusion & Future prospects for project
2009 Summer Alumni Trainee Meeting

3. Project: Ups & Downs of AB Dor
Project Description
AB Doradus is a pre main sequence star which generates wildly varying X-rays, going up and down in a few hours.
XMM-Newton has observed it many times to help maintain the instruments aboard the spacecraft.
This project will investigate how the x-ray emission spectrum changes during its ceaseless activity.
Motivation
Large amount of data not yet analysed
2009 Summer Alumni Trainee Meeting

4. AB Dor Characteristics
Zero-Age-Main-Sequence Star (ZAMS), spectral type KO-K1 V
Tertiary System:
AB Dor A & AB Dor B separated by 12 arcsecs
Impossible to resolve with EPIC & RGS
Jan-Uwe Ness : Chandra observation Relative intensity of emission 5%
Prot d
X-Ray emission from hot corona
Sunspots
2009 Summer Alumni Trainee Meeting

5. XMM Launched in 1999 Instruments
2 RGS (reflective grating spectrometer)
keV energy range
Effective area keV
FOV 5´
2 EPIC (European Photon Imaging Camera) MOS type imagers
keV energy range
Effective area 922 1keV
FOV 33 ´ X 33 ´
1 EPIC PN type imager
0.1 – 15 keV energy range
Effective area keV
FOV 27.5 ´ X 27.5 ´
1 OM (optical monitor)
2009 Summer Alumni Trainee Meeting

6. XMM Observations AB Dor observed 31 times Majority of them for
calibration purposes
Useable observations:
31 RGS observations – 66 exposures
MOS observations – 50 exposures
PN observations – 4 exposures
2009 Summer Alumni Trainee Meeting

7. PN Small Mode Result: 4 Useable PN observations
Total of 45 PN exposures
(discounting timing mode)
Of these 24 are closed calibration exposures
Of the remaining 21, 17 are small window mode
2009 Summer Alumni Trainee Meeting

8. Data Reduction & Analysis
SAS: Scientific Analysis System
Specifically designed to reduce and analyze data from XMM
Reduction – odfingest, rgsproc with src coordinates, ep(m)proc etc .....
Spectra & lightcurve extraction – rgslccorr, epiclccorr, evselect etc
XSPEC – X-Ray spectral fitting Package
2009 Summer Alumni Trainee Meeting

9. Light Curves Red: RGS Blue: MOS Green: PN
2009 Summer Alumni Trainee Meeting

10. Generating Simultaneous Light Curves
RGS generally turns on first – use T start as reference time
Pass this time as argument to rgslccorr & evselect
Need to check filters & mode to make sure a certain exposure is suitable
For Epic - need to select regions for extraction of source & background
Can be up to 12 eventlists per observation – tedious!
2009 Summer Alumni Trainee Meeting

11. XMMlccorr
Perl script to automatically generate exactly simultaneous light curves for all 5 of XMM’s instruments for one observation using SAS packages
Completely Automatic – directories cont
Extract observation start times, mode & filters from event files
Automatic source & background expression generation for EPIC exposures based on operation modes
Convert source coordinates to detector coordinates using SAS tool – esky2det
Depending on mode background is extracted from different regions
Generate simultaneous light curves
2009 Summer Alumni Trainee Meeting

12. Simultaneous light curve
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13. 2009 Summer Alumni Trainee Meeting

14. Spectra
2009 Summer Alumni Trainee Meeting

15. Conclusions so far.... Lot of work still to do
AB Dor – extremely variable over short time ranges
XMMlccorr – hopefully released as a SAS package
Lot of work still to do
Spectral analysis – look for rotational modulation in spectral lines
2009 Summer Alumni Trainee Meeting

16. Thanks! ESAC Andy Pollock All the trainees:
Jamie, Maria, Mael, Leila, Cecile, Bea, Ana & Cherry
Especially Maria!! Cos she is so (super)cool!
And
Antonio!
2009 Summer Alumni Trainee Meeting