long term monitoring of agns with bell astrophysical observatory whitney wills western kentucky...
TRANSCRIPT
Long Term Monitoring of AGNs with Bell
Astrophysical Observatory
Whitney WillsWestern Kentucky UniversityAdvisor: Dr. Michael Carini
Bell Astrophysical Observatory
Manufacturer: Group 128Primary Diameter: 0.6mf-ratio: 11Design: True CassegrainStarted buildingin 1975
Bell Astrophysical Observatory
Refurbishment 1999-2000Apogee Ap2p CCD cameraImage scale: 0.59arc/pixel, binned 2x2
Major Projects at Bell
AGN Monitoring – Dr. Michael CariniTransiting Extra Solar Planets – Dr. Charles McGruderMonitoring of Wolf-Rayet Stars – Dr. Sergey MarchenkoHOU – Dr. Barnaby
Jupiter and Saturn Week 2002-2003
ObservationsStudent run sessions from WKU’s campus or onsite3-180 second images in red filter
What are Active Galactic Nuclei?
1 Normal galaxy
Normal Galaxies
Spiral: M31
Elliptical: M87
Irregular: LMC
What are Active Galactic Nuclei?
1 Normal galaxy + 1 super massive black hole at
center
Super Massive Black Hole
What are Active Galactic Nuclei?
1 Normal galaxy + 1 super massive black hole at
center+ 1 accretion disk
Accretion Disk
What are Active Galactic Nuclei?
1 Normal galaxy + 1 super massive black hole at
center+ 1 accretion disk+ 2 relativistic jets of material
Relativistic Jets
What are Active Galactic Nuclei?
1 Normal galaxy + 1 super massive black hole at
center+ 1 accretion disk+ 2 relativistic jets of material=AGN
Active Galactic Nuclei
What are BL Lacertae Objects?
The most extreme example of an AGNHighly variable polarizationFeatureless optical spectraHighly variable continuum emission at all wavelengths
Why Study Them?
Featureless continuum means continuum radiation is the only diagnosticThey vary so why not?Variability is not regular, can’t get a few cycles and be finishedModels of AGNs need dataDr. Carini needs something to keep him out of trouble
ReductionsImage Reduction and Analysis Facility (IRAF)Removed background and thermal noise from the pictures (Bias and Dark levels) and removed non-linearity (flat field) Measured the brightness inside a circular aperture centered on the star
Before Reduction
After Reduction
Finding the Aperture
Used an image examiner tool in IRAF Found the full width, half max of the point spread function of the object and each of the comparison starsTook the average of the fwhm and used it as the aperture radius in a parameter in IRAF
Calculating Magnitudes & Errors
Take the magnitudeSubtract comparison star(s) from the object (gives a difference)Add back the standard value of the comp starsGives the mag value of your observationDo this for each image during the observation then average and take the standard deviation between each of the images
Results - Light CurvesBL Lac
13.50
13.60
13.70
13.80
13.90
14.00
14.10
14.20
14.30
14.40
14.50
2001.40 2001.60 2001.80 2002.00 2002.20 2002.40 2002.60 2002.80 2003.00 2003.20
Fractional Year
R M
agn
itu
de
Results - Light CurvesOJ 287
13.6
13.8
14
14.2
14.4
14.6
14.8
15
15.2
15.4
15.6
2001 2001.5 2002 2002.5 2003 2003.5
Fractional Year
R M
ag
nit
ud
e
Results - Light Curves3C 66A
14.1
14.2
14.3
14.4
14.5
14.6
14.7
14.8
14.9
15
15.1
2001.5 2002 2002.5 2003 2003.5
Fractional Year
R M
ag
nit
ud
e
Results - Light CurvesAO 0235+164
15.5
16
16.5
17
17.5
18
18.5
19
2001.6 2001.8 2002 2002.2 2002.4 2002.6 2002.8 2003 2003.2
Fractional Year
R M
agn
itu
de
Results - Light CurvesMRK 501
13.2
13.3
13.4
13.5
13.6
13.7
13.8
2001.2 2001.4 2001.6 2001.8 2002 2002.2 2002.4 2002.6 2002.8 2003
Fractional Year
R M
agn
itu
de
Results - Light Curves3C 454.3
13.5
14
14.5
15
15.5
16
16.5
2001.6 2001.8 2002 2002.2 2002.4 2002.6 2002.8 2003
Fractinal Year
R M
ag
nit
ud
e
AcknowledgementsTelescope Operators: Dr. Michael Carini Dr. David Barnaby Ashley Atkerson D. Allen Glass Tala Monroe Charles Poteet Wes Ryle Whitney Wills
Data Analysts: Dr. Michael Carini Whitney Wills
This project has been supported by NASA, the Kentucky Space Grant Consortium and the Applied Research and Technology Program at WKU
Questions?