NSF IRES 2009 Shashi M. Kanbur SUNY Oswego May-August 2009

Introduction  3 weeks here, 6 weeks in Brazil.  May 26 th -June12th: July 10 th -Aug 20 th.  Oswego: AM: Portuguese, PM: talks/Chimera/Astro projects.  This PM: get ID cards, parking, computer accounts, sign papers to get stipends, deliver Visa plus other other forms to OIEP.  Have intro talk on Chimera?

Chimera  Chimera is a robotic telescope control system.    Ubuntu 10.8 on laptop.  Download subversion, download source, use install script.  Install Chimera on laptop with setup.py  Currently at version 453. Upgrade from version 415.

LNA

UFSC, Antonio Kanaan, Paulo Henrique da Silva  Its tough to get time on telescopes.  Need long periods of time.    mapas.html mapas.html mapas.html

Chimera  Software system to robotically control a telescope.  Much of it written.  Need to work on photometry/extinction/seeing modules.  Mainly testing these and the rest of Chimera.

Photometry  CCD: Charge Coupled Device: rely on photoelectric effect.  Point telescope to star: add up the “signal” centered around the star – this is aperture photometry.  Extinction: how does the “signal” from a given star vary during the night?  Seeing: FWHM.

Cepheid Variables  Pulsating stars, periods of the order of days.  Period is related to their absolute magnitude.  m-M = 5log(d) – 5  Relation between M and logP is the Period-Luminosity (PL) relation.  Fundamental way to measure distances in the Universe.

Why?  Hubble’s law: v = Hd  Get v from Doppler shift of spectral lines.  Get d from extra-galactic distance ladder.  Slope gives H, Hubble’s constant – most fundamental constant in Astrophysics.  Sets size scale, age scale and fate/past of Universe.  Know it to 10% precision, want to know it to < 1% precision.

Cepheid PL relation  M = a+blogP  But is it linear?  My work suggests it is nonlinear, at least in the LMC.  All astrophysics projects have this as motivation: further testing, impact on H, theoretical modeling, data analysis.

Projects  Multiphase PC/PL relations.  Impact on H of linear/nonlinear PL relation using OGLE III data.  M3/M15 Oosterhoff dichotomy for RR Lyraes.  Astronomical data reduction of a large new set of data.  Statistical analysis of existing data.

Multiphase PC/PL

Compare with models.

Impact on H  Calibrate the SNIa diagram.  With OGLE II data, difference in H of about 1-2%.  With OGLE III data, difference in H of about 5%.  Check!!!  Work on multiphase OGLE III data, compare with observations.

NGC 4258  Water maser galaxy for which an accurate geometric distance exists.  Have the data for Cepheids in this galaxy.  Is the Cepheid PL relation in NGC 4258 linear or non-linear.  Write program to analyze data.  Apply F test, testimator, SIC etc. to investigate linearity/nonlinearity.

Oosterhoff dichotomy in M3/M15  Study data and theoretical models for RR Lyraes in M3/M15.  Investigate Oosterhoff dichotomy in terms of PC/AC relations.  Does Oosterhoff dichotomy manifest itself in PC/AC relations as a function of phase.  PC relation flat at minimum light?  Use as a reddening indicator?

Data Reduction  Work through IRAF data reduction procedures and daophot photometry procedures for a large (330Gb data set) of Cepheid observations for the LMC in IR.  Work on Sloan data set.  Produce documentation and cookbook.  Primary standards/secondary standards.

Statistical Analysis of Data  Cubic polynomial fits to M33 data.  Testimator as a test of heteroskedasticity.  Fourier/PCA analysis of other variable star datasets.  PC/PL relation linear in M31/M33?  IRAC bands PL relations.

Expectations  Learn Python, OOP.  Become familiar with Chimera, its structure and operation.  Work on Chimera and work on one of the research projects.  Need to write a report plus powerpoint poster on the Chimera work at the end of the project.  Right now, become familiar with chimera and OOP. Play around with it.  Work.

Schedule  AM: Portuguese.  Lunch.  PM (talks by me or by other faculty)  Tuesday May 26 th : PM: Admin  Wednesday May 27 th : Chimera Intro plus projects.  Thursday May 28 th : 2pm Dr. Alex Pantaleev: Object Orientated Programming.  Friday May 29 th : PM: Chimera plus projects.  Monday June 8 th : PM: Gravitational Wave Astronomy.  Tuesday June 9 th : PM: Physical Chemistry.