16927 - Astrophysics Laboratory

Learning outcomes

The student is guided to acquire a first experience with the basic instrumentation for astronomical observation from ground and space. He learns about the main parameters characterizing instrumental performances. In the lab activity he learns up-to-date techniques for acquisition and analysis of astronomical data in various bands: Optical/IR, Radio, X-rays. Within a small group, the student is lead to present his results in oral and/or written form.

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- OpticalAstronomylab(Where:CassiniTelescope,Loiano-Who:teachersB.Marano,S.Galleti )

1a-Opticaltelescopes (space and ground based): Classical Telescopes. The Hubble Space Telescope. New generation telescopes. 1b - Astronomicalpotometry:Colorsystems.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:Spectroscopyofgalacticandextragalacticsources; production of a spectral atlas of bright stars; spectra of diffuse galactic sources. Observation and analysis of a selection among: spectra of galaxies, AGNs, QSOsandCCD 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, M.Orienti, T.Venturi)
3a - Radiotelescopes - Interferometry and aperture syntesis. 3b - detection of radio waves. Radioobservations. 3c-Interferometerandmeasureofthefringevisibility.Fourierinversionandskybrightness.Methodsofdeconvolutionofimagesandimage analysis 3d- Reconstruction ofthe imageofaradiogalaxy frominterferometric data from archive, with determination of physical parameters of the source.

Readings/Bibliography

Most of the activity is described in Powerpoint presentations, available at https://campus.unibo.it, and in paperssuggestedduringthelabwork.

Someusefultexts are:


Kitchin, Astrophysical techniques, Philadelfia Inst. of Physics

- Schroeder,Astronomical Optics, Associated Press

- Léna, Lebrun, Mignard - Observational Astrophysics, Springer

- Glenn F. Knoll - Radiation Detectors for X-Ray and Gamma-Ray Spectroscopy - Third Edition (2000) - John Wiley & Sons

Teaching methods

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

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 Paola Grandi