NSF IRES 2009NSF IRES 2009

Shashi M. KanburShashi M. Kanbur

SUNY Oswego May-August 2009SUNY Oswego May-August 2009

IntroductionIntroduction

3 weeks here, 6 weeks in Brazil.3 weeks here, 6 weeks in Brazil. May 26May 26thth-June12th: July 10-June12th: July 10thth-Aug 20-Aug 20thth.. Oswego: AM: Portuguese, PM: Oswego: AM: Portuguese, PM:

talks/Chimera/Astro projects.talks/Chimera/Astro projects. This PM: get ID cards, parking, computer This PM: get ID cards, parking, computer

accounts, sign papers to get stipends, accounts, sign papers to get stipends, deliver Visa plus other other forms to deliver Visa plus other other forms to OIEP.OIEP.

Have intro talk on Chimera?Have intro talk on Chimera?

ChimeraChimera

Chimera is a robotic telescope control system.Chimera is a robotic telescope control system. http://code.google.com/p/chimerahttp://code.google.com/p/chimera http://code.google.com/p/csc480-chimerahttp://code.google.com/p/csc480-chimera Ubuntu 10.8 on laptop.Ubuntu 10.8 on laptop. Download subversion, download source, use Download subversion, download source, use

install script.install script. Install Chimera on laptop with setup.pyInstall Chimera on laptop with setup.py Currently at version 453. Upgrade from version Currently at version 453. Upgrade from version

415.415.

LNALNA

UFSC, Antonio Kanaan, Paulo UFSC, Antonio Kanaan, Paulo Henrique da SilvaHenrique da Silva

Its tough to get time on telescopes.Its tough to get time on telescopes. Need long periods of time.Need long periods of time. http://http://www.ufsc.brwww.ufsc.br http://www.astro.ufsc.brhttp://www.astro.ufsc.br http://www.astro.ufsc.br/extensao/mapas/http://www.astro.ufsc.br/extensao/mapas/

mapas.htmlmapas.html

ChimeraChimera

Software system to robotically control a Software system to robotically control a telescope.telescope.

Much of it written.Much of it written. Need to work on Need to work on

photometry/extinction/seeing modules.photometry/extinction/seeing modules. Mainly testing these and the rest of Mainly testing these and the rest of

Chimera.Chimera.

PhotometryPhotometry

CCD: Charge Coupled Device: rely on CCD: Charge Coupled Device: rely on photoelectric effect.photoelectric effect.

Point telescope to star: add up the “signal” Point telescope to star: add up the “signal” centered around the star – this is aperture centered around the star – this is aperture photometry.photometry.

Extinction: how does the “signal” from a Extinction: how does the “signal” from a given star vary during the night?given star vary during the night?

Seeing: FWHM.Seeing: FWHM.

Cepheid VariablesCepheid Variables

Pulsating stars, periods of the order of Pulsating stars, periods of the order of days.days.

Period is related to their absolute Period is related to their absolute magnitude.magnitude.

m-M = 5log(d) – 5m-M = 5log(d) – 5 Relation between M and logP is the Relation between M and logP is the

Period-Luminosity (PL) relation.Period-Luminosity (PL) relation. Fundamental way to measure distances in Fundamental way to measure distances in

the Universe.the Universe.

Why?Why?

Hubble’s law: v = HdHubble’s law: v = Hd Get v from Doppler shift of spectral lines.Get v from Doppler shift of spectral lines. Get d from extra-galactic distance ladder.Get d from extra-galactic distance ladder. Slope gives H, Hubble’s constant – most Slope gives H, Hubble’s constant – most

fundamental constant in Astrophysics.fundamental constant in Astrophysics. Sets size scale, age scale and fate/past of Sets size scale, age scale and fate/past of

Universe.Universe. Know it to 10% precision, want to know it Know it to 10% precision, want to know it

to < 1% precision.to < 1% precision.

Cepheid PL relationCepheid PL relation

M = a+blogPM = a+blogP But is it linear?But is it linear? My work suggests it is nonlinear, at least My work suggests it is nonlinear, at least

in the LMC.in the LMC. All astrophysics projects have this as All astrophysics projects have this as

motivation: further testing, impact on H, motivation: further testing, impact on H, theoretical modeling, data analysis.theoretical modeling, data analysis.

ProjectsProjects

Multiphase PC/PL relations.Multiphase PC/PL relations. Impact on H of linear/nonlinear PL relation Impact on H of linear/nonlinear PL relation

using OGLE III data.using OGLE III data. M3/M15 Oosterhoff dichotomy for RR M3/M15 Oosterhoff dichotomy for RR

Lyraes.Lyraes. Astronomical data reduction of a large new Astronomical data reduction of a large new

set of data.set of data. Statistical analysis of existing data.Statistical analysis of existing data.

Multiphase PC/PLMultiphase PC/PL

Compare with models.Compare with models.

Impact on HImpact on H

Calibrate the SNIa diagram.Calibrate the SNIa diagram. With OGLE II data, difference in H of With OGLE II data, difference in H of

about 1-2%.about 1-2%. With OGLE III data, difference in H of With OGLE III data, difference in H of

about 5%.about 5%. Check!!!Check!!! Work on multiphase OGLE III data, Work on multiphase OGLE III data,

compare with observations.compare with observations.

NGC 4258NGC 4258

Water maser galaxy for which an accurate Water maser galaxy for which an accurate geometric distance exists.geometric distance exists.

Have the data for Cepheids in this galaxy.Have the data for Cepheids in this galaxy. Is the Cepheid PL relation in NGC 4258 Is the Cepheid PL relation in NGC 4258

linear or non-linear.linear or non-linear. Write program to analyze data.Write program to analyze data. Apply F test, testimator, SIC etc. to Apply F test, testimator, SIC etc. to

investigate linearity/nonlinearity.investigate linearity/nonlinearity.

Oosterhoff dichotomy in M3/M15Oosterhoff dichotomy in M3/M15

Study data and theoretical models for RR Study data and theoretical models for RR Lyraes in M3/M15.Lyraes in M3/M15.

Investigate Oosterhoff dichotomy in terms Investigate Oosterhoff dichotomy in terms of PC/AC relations.of PC/AC relations.

Does Oosterhoff dichotomy manifest itself Does Oosterhoff dichotomy manifest itself in PC/AC relations as a function of phase.in PC/AC relations as a function of phase.

PC relation flat at minimum light?PC relation flat at minimum light? Use as a reddening indicator?Use as a reddening indicator?

Data Reduction Data Reduction

Work through IRAF data reduction Work through IRAF data reduction procedures and daophot photometry procedures and daophot photometry procedures for a large (330Gb data set) of procedures for a large (330Gb data set) of Cepheid observations for the LMC in IR.Cepheid observations for the LMC in IR.

Work on Sloan data set.Work on Sloan data set. Produce documentation and cookbook.Produce documentation and cookbook. Primary standards/secondary standards.Primary standards/secondary standards.

Statistical Analysis of DataStatistical Analysis of Data

Cubic polynomial fits to M33 data.Cubic polynomial fits to M33 data. Testimator as a test of heteroskedasticity.Testimator as a test of heteroskedasticity. Fourier/PCA analysis of other variable star Fourier/PCA analysis of other variable star

datasets.datasets. PC/PL relation linear in M31/M33?PC/PL relation linear in M31/M33? IRAC bands PL relations.IRAC bands PL relations.

ExpectationsExpectations

Learn Python, OOP.Learn Python, OOP. Become familiar with Chimera, its structure and Become familiar with Chimera, its structure and

operation. operation. Work on Chimera and work on one of the Work on Chimera and work on one of the

research projects.research projects. Need to write a report plus powerpoint poster on Need to write a report plus powerpoint poster on

the Chimera work at the end of the project.the Chimera work at the end of the project. Right now, become familiar with chimera and Right now, become familiar with chimera and

OOP. Play around with it.OOP. Play around with it. Work.Work.

ScheduleSchedule

AM: Portuguese.AM: Portuguese. Lunch.Lunch. PM (talks by me or by other faculty)PM (talks by me or by other faculty) Tuesday May 26Tuesday May 26thth: PM: Admin: PM: Admin Wednesday May 27Wednesday May 27thth: Chimera Intro plus projects.: Chimera Intro plus projects. Thursday May 28Thursday May 28thth: 2pm Dr. Alex Pantaleev: Object : 2pm Dr. Alex Pantaleev: Object

Orientated Programming.Orientated Programming. Friday May 29Friday May 29thth: PM: Chimera plus projects.: PM: Chimera plus projects. Monday June 8Monday June 8thth: PM: Gravitational Wave Astronomy.: PM: Gravitational Wave Astronomy. Tuesday June 9Tuesday June 9thth: PM: Physical Chemistry.: PM: Physical Chemistry.