16927 - Astrophysics Laboratory

Course contents

The introductory part deals with fundamental concepts: detection of EM radiation, signal to noise ratio, instrumental resolution, PSF. Three "full immersion" laboratory sessions follow (Xray, Optical, Radio). Students are organized in small groups and shifts.   A number of teachers, expert  in the various techniques, guide the students in the lab work.     

General Introduction (Where: Dept. of Astronomy. Who: teacher B. Marano - 16 hours)   
1 - Spectrum of the electromagnetic radiation. Atmospheric transmission as a function of the wavelength.
2 - Detectors of optical and infrared radiation; their characterization. Sources of instrumental noise (dark current, read out noise). Photoelectric photometer and CCD.
3 - Poisson statistics. Signal to noise ratio (SNR)  in astronomical observations. Sky background in Optical and Infrared.  SNR in photon limited and background limited observations.
4 - Construction of a basic exposure time calculator (ETC), estimate of the exposure time, comparison between ground and space telescopes. Use of ETC in the web (ESO; TNG)
5 - Angular resolution. Point Spread Function (PSF). Modulation Transfer Function (MTF). Image sampling.


Laboratories (in shifts)

1- Optical Astronomy lab (Where: Cassini Telescope, Loiano - Who: teachers B.Marano, S.Galleti, V.Zitelli )

1a -  Optical   telescopes  (space and ground based):  Classical Telescopes. The Hubble Space Telescope. New generation telescopes. 1b - Astronomical potometry: Color systems. PSF, diffraction, seeing. Seeing correction: adaptive optics.  1c - Astronomical spectroscopy: Optical scheme of spectrographs. Analysys of spectra. Measurement of radial velocities in astronomical spectra. 1d - Observations: Spectroscopy of galactic and extragalactic sources; production of a spectral atlas of bright stars; spectra of diffuse galactic sources. Observation and analysis of a selection among:  spectra of galaxies, AGNs, QSOs and CCD photometry of an open cluster.


2 - X-ray Lab (Where: INAF-IASF, Bologna - Teachers. C.Vignali, P.Grandi, M. Dadina)     
2a - X-Ray and Gamma Ray detectors    2b - Instruments on board of the main active X-ray satellites (Chandra, XMM-Newton; Suzaku). Introduction to future missions.   2c - Data Analysis. Basics:  statistics, PSF, angular resolution, energy resolution, time resolution, field of view, instrumental response.   2d - Data acquisition from public archives, production of light curves,images and spectra. Selection among: morphology of extended sources, time variability, spectral analysis (continuum and lines); detection of sources in deep fields. 
 
3 - Radio Lab (Where: INAF-IRA,Bologna. Who: teachers D.Dallacasa, T.Venturi)      
3a - Radiotelescopes - Interferometry and aperture syntesis.    3b - detection of radio waves. Radio observations.  3c - Interferometer and measure of the fringe visibility. Fourier inversion and sky brightness. Methods of deconvolution of images and image analysis     3d - Reconstruction of the image of a radiogalaxy from interferometric data from archive, with determination of physical parameters of the source.

Readings/Bibliography

Most of the activity is described in Powerpoint presentations and in papers suggested during the lab work. Some useful texts are:


Kitchin, Astrophysical techniques, Philadelfia Inst. of Physics

- Schroeder,  Astronomical Optics, Associated Press 

- Léna, Lebrun, Mignard - Observational Astrophysics, Springer

Teaching methods

Conventional class lectures. Laboratory activity in small groups. Preparation and discussion of reports.

Assessment methods

At the end of each laboratory session, work done and results are presented in written reports or oral presentations. Activity, reports and presentation are evaluated and concur in a global evaluation which is at end given after an exam on the introductory part and on the activities performed by the student.

Teaching tools

After the introductory part, the activity moves to three research institutes. Students will perform in small groups  observations (in optical), data base searches, data reduction, and data analysis ,with instruments in use in the current astronomical research.

Office hours

See the website of Bruno Marano

See the website of Daniele Dallacasa

See the website of Cristian Vignali

See the website of Silvia Galleti

See the website of Paola Grandi

See the website of Tiziana Venturi