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?