This presentation briefly explains the main steps for the spectroscopic analysis of Quasar by IRAF (image reduction and analysis facility).

2. Contents
 What is AGN?
 What differentiates a Quasar?
 Our Source
 Charge Couple Device (CCD)
 Spectroscopy
 Image Cleaning
 Wavelength calibration
 Flux calibration
 Results
 Conclusions

3. What is AGN?
An active galactic nucleus (AGN) is a compact region at the center of a
galaxy. They are highly energetic manifestations, believed to be
powered by accretion onto massive black holes. It outshines the host
galaxy such that the rest of it is not visible in most of the
electromagnetic spectrum.
All AGNs are really the same
type of objects, but viewed
from different angles.

4. Quasars
What are QUASARS?
## A class of AGNs with following characteristics:
● star-like object identified with a radio source,
● variable light,
● broad emission lines in the spectra with absorption lines
in some cases,
● large redshift.
Properties: 1. Most powerful object
2. Multi wavelength astronomy
3. Large distances z<0.1 to z>7
4. Help us to peep into past

5. Our Sources
 Source Name: 2QZ J104513.7+002644
RA:10 45 13.76
Dec: +00 26 44.3
 Source 2: 2QZ J122338.0-015619
RA: 12 23 38.058
Dec: -01 56 17.16
 Type: RQWLQ (Radio Quiet Weak emission Line
Quasar)
 No jets (radio-quiet)
 Weak emission lines in their spectra.

6. Charge Coupled Device (CCD)
 Working
 Quantum Efficiency
 Linearity
 Noise :
1. Dark Current
2. Read Out Noise
 Gain

7. Spectroscopy
 Difference between Photometry and Spectroscopy
 Definition: Response of Matter to EM Radiation
 Importance
 Spectrum Types: 1. Continuous
2. Emission
3. Absorption

8. Image Cleaning
Noise
 Biasing
 Pixel to pixel sensitivity
variation
Corrections
 Bias correction
 Flat correction

9. Noises
 Dark-current
 Cosmic ray
Corrections
 CCD cooling
 Cosmic ray removal

10. Wavelength Calibration
In Wavelength calibration, IRAF follows given tasks
 apall: (To extract the spectrum from dispersion axis to
in form of pixel and pixel count )

11.  identify: to give the wavelength values to pixels,
 hedit: to update this information to our OBJ and
STD star,
 dispcor: to apply this wavelength calibration
to our OBJ and STD star spectrum.

13. Flux Calibration
 The process of determining the continuum flux at
each wavelength from the measured pixel counts.
 IRAF commands for flux calibration:
standard: tabulate the observed pixel counts of
standard star with flux
sensfunc: calculate the sensitivity curve and fit
calibrate: apply the sensitivity curve to the
observed object.

14. Results

17. Conclusions
 As stars are known to have black body spectrum, but we
got a power law spectrum. So our Source can not be a Star.
It could be an AGN.
 The spectrum looks like that of BLAZARs (no strong
emission or absorption lines) but the source is radio quiet in
nature. Therefore, these sources could be long debated
radio quiet BLAZARs.

18. THANK YOU