Redshifts and optical identification of a sample of scintillating flat spectrum radio sources

How to screw up a slit viewing camera Tapio Pursimo & Maria Monguio i Montells Marilena Spavone Ingo Misgeld Jonas Johansson

The MASIV survey intraday variability (IDV) of extragalactic sources at centimeter wavelengths interstellar scintillation as an explanation caused by the turbulent, ionized ISM Aim: optical identification of a larger sample of IDV sources and determination of redshifts

Observations Spectroscopy and imaging with NOT/ALFOSC (Andalucia Faint Object Spectrograph and Camera) Spectroscopy with INT/IDS (Intermediate Dispersion Spectrograph)‏

Spectra Reduction Trimming Bias subtraction Overscan region

Flat Fielding

Sky subtraction

1D Spectra Img4=>img5

Spectra Reduction Wavelenght calibration: Calibrate the arc:

Apply the calibration to the spectra:

Blocking filter For some spectra we used a blocking filter We use the blocking filter to block the second order.

J MgII => CIII => Z=1,3 img9

J MgII => CIII => Z=1,58 img10

J There are no lines. The spectrum is to noisy We need high SNR It is an BLLAC object

Reduction of imaging data

Bias frame

Skyflat

Reduction of imaging data

Reduced image

J sec exposure in R-band magnitudes estimated with fieldstars from the Guide Star Catalogue (GSC) => R ~ 17.2 mag limiting magnitude ~ 20.3 mag

ToO: SN2008dq

SN2008dq 60 & 300 sec in R-band 300 sec in V-band magnitude estimation with GSC stars in the field R SN ~ 18.6 mag & 18.2 mag V SN ~ 18.4 mag limiting magnitude on deep images ~ 22 mag

Does it make sense? T.P.