Astrophysics Research Astrophysics Research Projects for NSF IRES May-Projects for NSF IRES May-

July-August 2008July-August 2008

Shashi M. Kanbur Shashi M. Kanbur

(SUNY Oswego)(SUNY Oswego)

Antonio Kanaan (UFSC)Antonio Kanaan (UFSC)

Cepheid VariablesCepheid Variables Linear relation between logP and M (in a number Linear relation between logP and M (in a number

of different bands).of different bands). Is this relation non-linear: at least in the LMC Is this relation non-linear: at least in the LMC

optical wavebands, data suggests that it is.optical wavebands, data suggests that it is. Modeling, look at other wavelengths, Modeling, look at other wavelengths,

apply/develop new statistical tests.apply/develop new statistical tests. Look at data from other galaxies.Look at data from other galaxies. Reduce new set of IR data.Reduce new set of IR data. Use http://xxx.lanl.govUse http://xxx.lanl.gov Use Use

http://adsabs.harvard.edu/abstract_service.htmlhttp://adsabs.harvard.edu/abstract_service.html

Application of new Statistical Application of new Statistical MethodsMethods

Kanbur, Ngeow, Nanthakumar and Stevens (2007) developed the Kanbur, Ngeow, Nanthakumar and Stevens (2007) developed the testimator and Schwarz Information Criterion methods to LMC testimator and Schwarz Information Criterion methods to LMC OGLE data.OGLE data.

Code this up and apply it to SMC OGLE data/DIRECT M31/M33 Code this up and apply it to SMC OGLE data/DIRECT M31/M33 data plus any other Cepheid data sets that you can find.data plus any other Cepheid data sets that you can find.

Ngeow and Kanbur (2008) developed a mid-infrared PL relation. Ngeow and Kanbur (2008) developed a mid-infrared PL relation. Nanthakumar and Kanbur (2009) developed an adaptation of the Nanthakumar and Kanbur (2009) developed an adaptation of the testimator to check for changing dispersion as a function of period – testimator to check for changing dispersion as a function of period – apply this to the Spitzer data plus at other wavelengths.apply this to the Spitzer data plus at other wavelengths.

Develop the use of cubic splines to analyze variable star light curves Develop the use of cubic splines to analyze variable star light curves – start of with an M31 RR Lyrae dataset.– start of with an M31 RR Lyrae dataset.

Apply the methods of Koen Kanbur and Ngeow (2007) to other data Apply the methods of Koen Kanbur and Ngeow (2007) to other data sets eg the OGLE SMC data. This involves using the stats package sets eg the OGLE SMC data. This involves using the stats package “R” in a Linux environment.“R” in a Linux environment.

The papers mentioned above are at The papers mentioned above are at www.oswego.edu/~kanbur/research.htmlwww.oswego.edu/~kanbur/research.html

Cepheid IR data reductionCepheid IR data reduction

Become familiar with IR data reduction and Become familiar with IR data reduction and photometry as outlined in documents generated photometry as outlined in documents generated by Frank Ripple/Travis Rooker/Dan Crain.by Frank Ripple/Travis Rooker/Dan Crain.

Try to automate this – in Python and see how Try to automate this – in Python and see how these methods may change for the optical.these methods may change for the optical.

Construct CMD diagrams and look for the TRGB Construct CMD diagrams and look for the TRGB using a number of statistical methods – code this using a number of statistical methods – code this up – look at Makarov, D., et al 2006.up – look at Makarov, D., et al 2006.

Cepheid IR PCACepheid IR PCA

Work on Cepheid IR PCA analysis.Work on Cepheid IR PCA analysis. Check work thoroughly.Check work thoroughly. Other datasets?Other datasets? Can this be used to generate Cepheid light Can this be used to generate Cepheid light

curve templates in the IR?curve templates in the IR? Fit polynomials to PCA progressions with Fit polynomials to PCA progressions with

period – compare with Tanvir et al 2005.period – compare with Tanvir et al 2005.

Finish of this paper.Finish of this paper.

RR LyraesRR Lyraes Look at M31 RR Lyraes – which is better Fourier/cubic Look at M31 RR Lyraes – which is better Fourier/cubic

splines/PCA?splines/PCA? Construct PC/AC relations as a function of phase for Construct PC/AC relations as a function of phase for

M31 RR Lyraes: fit lines/polynomials to observed M31 RR Lyraes: fit lines/polynomials to observed progressions – compare with other data?progressions – compare with other data?

Relate metallicity to Galactic RR Lyraes using PCA: I Relate metallicity to Galactic RR Lyraes using PCA: I have Galactic RR Lyrae data for which the metallicity have Galactic RR Lyrae data for which the metallicity and well observed light curves are available – relate light and well observed light curves are available – relate light curve structure through PCA to metallicity using curve structure through PCA to metallicity using regression methods.regression methods.

Look at M3/M15 paper – are there any other datasets Look at M3/M15 paper – are there any other datasets that could be used? Analyze data given by Corwin. Any that could be used? Analyze data given by Corwin. Any other interesting correlations from the models – finish other interesting correlations from the models – finish this paper of. Look at Corwin et al (2008) for data on this paper of. Look at Corwin et al (2008) for data on M15. I have this paper.M15. I have this paper.

ModelingModeling Analysis of Marconi models – multiphase PL/PC relations – Analysis of Marconi models – multiphase PL/PC relations –

compare observed PC/AC relations as a function of phase with compare observed PC/AC relations as a function of phase with those from models.those from models.

Observed PC/AC relations can be found in my papers on Observed PC/AC relations can be found in my papers on www.oswego.edu/~kanbur/research.html. I have the theoretical www.oswego.edu/~kanbur/research.html. I have the theoretical models.models.

D-R front transition in ionization fronts in Cepheids: a mixture of D-R front transition in ionization fronts in Cepheids: a mixture of theory and numerical analysis.theory and numerical analysis.

LNA analysis for Elio Antonello – change existing code to solve up LNA analysis for Elio Antonello – change existing code to solve up to 14to 14thth or 15 or 15thth order. Current code goes up to 6 order. Current code goes up to 6thth order. Check. Then order. Check. Then run models. Could possibly have a poster for a meeting in Liege, run models. Could possibly have a poster for a meeting in Liege, Belgium in July.Belgium in July.

RR Lyrae models?RR Lyrae models? Why does our code produce lower amplitudes? This is a hard Why does our code produce lower amplitudes? This is a hard

project.project.

Chimera Chimera

This is the name given to the Robotic This is the name given to the Robotic Telescope Project.Telescope Project.

Antonio Kanaan and Paulo Henrique at Antonio Kanaan and Paulo Henrique at UFSC.UFSC.

Also supported at LNA/OPD in Minas Also supported at LNA/OPD in Minas Gerais.Gerais.

Software control system in Python.Software control system in Python. Basics are working.Basics are working.

Web ReferencesWeb References

Python: Python: www.python.orgwww.python.org and and www.python.org/docswww.python.org/docs Please go through this and try to refresh/become familiar Please go through this and try to refresh/become familiar

with Python programming before you leave for Brazil. with Python programming before you leave for Brazil. Pay particular attention to the concept of classes.Pay particular attention to the concept of classes.

http://pytut.infogami.com/node11-baseline.htmlhttp://pytut.infogami.com/node11-baseline.html http://chimera.sourceforge.nethttp://chimera.sourceforge.net http://code.google.com/p/chimera/wiki/IRES2008http://code.google.com/p/chimera/wiki/IRES2008 http://chimera.googlecode.comhttp://chimera.googlecode.com http://groups.google.com/group/ires2008-oswego-http://groups.google.com/group/ires2008-oswego-

floripa?hl=enfloripa?hl=en

ChimeraChimera Follow instructions on chimera.sourceforge.net and try to install Chimera on Follow instructions on chimera.sourceforge.net and try to install Chimera on

machines (Ryann and Denis).machines (Ryann and Denis). Download current source code at Download current source code at

http://code.google.com/p/chimera/source/checkouthttp://code.google.com/p/chimera/source/checkout Here there is also a directory with examples (docs/examples). Look at Here there is also a directory with examples (docs/examples). Look at

server.py, client.py. Try to run these files with python server.py and then server.py, client.py. Try to run these files with python server.py and then python client.py.python client.py.

Look at minimo.py which contains examples of all main structures that you Look at minimo.py which contains examples of all main structures that you can add to a Chimera instrument. Look at classes used – the main Chimera can add to a Chimera instrument. Look at classes used – the main Chimera classes used.classes used.

Right now the source is the best documentation.Right now the source is the best documentation. Join the googlegroups – can start discussions on this with PH and AK and Join the googlegroups – can start discussions on this with PH and AK and

myself.myself. ““Look” at source and try to figure out how it works in conjunction with Look” at source and try to figure out how it works in conjunction with

discussions with Paulo Henrique. Really need someone to dicument this!discussions with Paulo Henrique. Really need someone to dicument this! Make sure you understand a bit about CCD imaging in Astronomy.Make sure you understand a bit about CCD imaging in Astronomy.

Data Reduction and CalibrationData Reduction and Calibration Data Reduction.Data Reduction. Read up about CCD’s.Read up about CCD’s. Go through handout on data reduction and try to think how you Go through handout on data reduction and try to think how you

might do this in Python. We will be doing this type of reduction for might do this in Python. We will be doing this type of reduction for Chimera though its not exactly the same.Chimera though its not exactly the same.

Write a routine to take a sky flat (point scope, take image, schedule Write a routine to take a sky flat (point scope, take image, schedule this appropriately).this appropriately).

Calibration: find out about bias, darks, flats and how to process Calibration: find out about bias, darks, flats and how to process them – the above exercise should help you. Most of these frames them – the above exercise should help you. Most of these frames can already be taken but need to integrate this into a smooth can already be taken but need to integrate this into a smooth procedure.procedure.

Look up the Tyson and Gal 1986 paper orLook up the Tyson and Gal 1986 paper or Chromey and Hasselbacher 1996 (use Chromey and Hasselbacher 1996 (use http://xxx.lanl.govhttp://xxx.lanl.gov and and

http://adsabs.harvard.edu/abstract_service.htmlhttp://adsabs.harvard.edu/abstract_service.html

Pointing VerificationPointing Verification Send the telescope to a given point. If you tell the scope Send the telescope to a given point. If you tell the scope

to go to RA, DEC, EPOCH, how can you be sure that to go to RA, DEC, EPOCH, how can you be sure that you are where you think you are? Mechanical you are where you think you are? Mechanical imperfections etc. SO identify the field and get imperfections etc. SO identify the field and get astrometric information from the image and make astrometric information from the image and make appropriate corrections and get map relating pixel appropriate corrections and get map relating pixel coordinates to RA, DEC, EPOCH so that the center pixel coordinates to RA, DEC, EPOCH so that the center pixel goes to RA, DEC, EPOCHgoes to RA, DEC, EPOCH

Take an image, run sextractor - an open source Take an image, run sextractor - an open source program to identify the stellar sources.program to identify the stellar sources.

Run wcstools to match the identified stars against a Run wcstools to match the identified stars against a catalogue of stellar positions (UCAC II).catalogue of stellar positions (UCAC II).

Find out about sextractor wcstools, UCAC II.Find out about sextractor wcstools, UCAC II. The above is a “poor man’s pointing model.The above is a “poor man’s pointing model.

Graphical User InterfaceGraphical User Interface

Uses pyGTK.Uses pyGTK. Front end interface to the whole system.Front end interface to the whole system. Need to input, observer name, Object Need to input, observer name, Object

name, RA and Dec, Julian date, number of name, RA and Dec, Julian date, number of images in each filter – some other stuff images in each filter – some other stuff regarding restrictions – discuss with PH.regarding restrictions – discuss with PH.

Also need to integrate this with a GUI for Also need to integrate this with a GUI for the whole system eg. If a user wants to the whole system eg. If a user wants to just adjust the focus and do nothing else.just adjust the focus and do nothing else.

TasksTasks So the CS guys should concentrate on looking at the So the CS guys should concentrate on looking at the

Chimera code and trying to understand it – then explain Chimera code and trying to understand it – then explain this to us perhaps? Perhaps after a while start working this to us perhaps? Perhaps after a while start working on the GUI interface and perhaps the pointing model?on the GUI interface and perhaps the pointing model?

Could be joined by the Physicists who are experienced in Could be joined by the Physicists who are experienced in Python: work in pairs.Python: work in pairs.

Physicists can also work on some of the Cepheid Physicists can also work on some of the Cepheid projects – would really like this to happen.projects – would really like this to happen.

For the pure science projects, can work in pairs or For the pure science projects, can work in pairs or individually – can work on these whilst in Brazil as well.individually – can work on these whilst in Brazil as well.

In Brazil there may be posssibilities to work on other In Brazil there may be posssibilities to work on other projects related to white dwarfs plus instrumentation projects related to white dwarfs plus instrumentation projects.projects.

MachinesMachines

At Oswego: 129.3.17.53 (rrlyrae) and 129.3.1.55 At Oswego: 129.3.17.53 (rrlyrae) and 129.3.1.55 (Cepheid) – this is a dual processor 64 bit AMD (Cepheid) – this is a dual processor 64 bit AMD machine. Both run Debian Linux. machine. Both run Debian Linux.

When off campus (perhaps on campus) can only When off campus (perhaps on campus) can only get to these machines through get to these machines through moxie.cs.oswego.edu.moxie.cs.oswego.edu.

Once you get your campus email address, you Once you get your campus email address, you will have an account on moxie.cs.oswego.edu.will have an account on moxie.cs.oswego.edu.

In Snygg, work in the moxie lab and ssh in. ssh In Snygg, work in the moxie lab and ssh in. ssh –X for graphical output.–X for graphical output.

OswegoOswego

Small college town.Small college town. Eating: College dining, Campus Center, Eating: College dining, Campus Center,

Subway, Fajita Grill, Aztecas, Rudy’s.Subway, Fajita Grill, Aztecas, Rudy’s. Shopping: minor groceries (milk, bread, Shopping: minor groceries (milk, bread,

eggs) at the Gas Station. Otherwise Price eggs) at the Gas Station. Otherwise Price Chopper etc. available at the other end of Chopper etc. available at the other end of town.town.

I can take you for this major shopping to I can take you for this major shopping to Price Chopper if you don’t have a car.Price Chopper if you don’t have a car.