96385 - MULTIWAVELENGTH ASTROPHYSICS LABORATORY

Learning outcomes

At the end of the course students will acquire knowledge about reduction, analysis and interpretation of data from ground-based and space-based facilities across a wide range of wavelengths, from radio (centimeter and millimeter) to optical/near-IR and X-rays/Gamma-rays. Modern techniques of astronomical data analysis will be acquired by the student, along with the capability of presenting and discussing professionaly the results of the analysis of measurements taken during the course.

Course contents

The course structure is intended to provide students with the capabilities to work as a team, read and understand scientific papers, and discuss their results using either written reports or PowerPoint presentations.

The course is organized into three lab courses, each focusing on topics at a different wavelength range. Together, the three labs comprise five modules in total (some labs include more than one module), allowing full exploitation of the competencies of researchers from the INAF-OAS and IRA institutes.
The three lab courses are:

• optical/near-IR (module 2);
• radio/millimeter [low frequency (VLA, module 5)/high frequency (ALMA, module 4)];
• high energy (X-ray/Gamma-ray/TeV; modules 1 and 3).

All students will attend the three laboratory courses. About the radio/millimeter laboratory, half of the students will attend the VLA lab (low frequency) and the remaining half the ALMA lab (high frequency) in parallel. Students can express their preference; however, the choice of either the VLA or the ALMA module is not so “important”, since the techniques acquired by the students are essentially the same.

Each lab comprises lessons on fundamentals in data analysis concepts (e.g., detection of astronomical signals, background, SNR, PSF, etc.), tutorials (preparatory for the subsequent data analysis), and hands-on training on data reduction, analysis, and interpretation.

Each lab lasts 3 weeks, allowing students the option of a fourth week to work more in depth on the data.

Students will be divided into working groups (typically, comprising 3 people). All of the available scientific projects will be presented during the frontal lessons (including reference papers). Each group will be assigned a specific scientific project and the corresponding datasets. Their analysis will require the most up-to-date techniques, explained in the tutorials. A fundamental part of these laboratory courses are discussions with teachers and experts of the fields.

In the following, a non-exhaustive list of general and specific (i.e., module-related) topics is reported:

Optical/near-IR module:

• Detection of astronomical signals. Transmission of the electromagnetic radiation through the atmosphere.
• Background and its treatment in astronomical data analysis.
• PSF and signal-to-noise ratio concepts.
• Photometry: photometric systems and basic concepts
• Spectroscopy of stars.
• Chemical abundances from stellar spectra.
• Kinematics: a measure of radial velocity and redshift from observed spectra.
• Properties of telescopes in different bands.
• Exposure time calculators.

Radio/millimeter module:

• Frontal lectures (~1 week): antenna fundamentals: patterns of reflector antennas, brief recap of Fourier Transforms, 2D aperture antennas, resolving powers; interferometers: complex correlator and visibility, aperture synthesis, data calibration, basics of imaging, clean & restore; peculiarities of mm-interferometry.
• Tutorial of VLA/ALMA data reduction and analysis (~1 week): CASA presentation, data inspection; basics of calibration, bandpass calibration, gain calibration; basics of imaging, clean & restore algorithm; final imaging and image analysis.
• Group work (~1 week): analysis of a new dataset, similar to the one used for the tutorial.

High-energy module:

Frontal lessons and tutorials (Chandra, XMM-Newton, and Fermi data) are typically confined in the first week of this module. Topics are related to:

• Grazing incident technique, X-ray focusing systems, and main X-ray telescope and detector concepts and parameters.
• Chandra vs. XMM-Newton properties.
• X-ray imaging, timing, and spectroscopy.
• Gamma-ray data analysis and pipelines.
• Pills of statistics with applications to X-ray/high-energy data.
• Excursus on the properties of the main modern telescopes and future facilities.
• Presentation of the science cases associated with the data that students will analyse.

Readings/Bibliography

Here we provide a list of textbooks where students can find useful material (besides slides, other material and papers that will be suggested during the course).

Detectors for high-energy astrophysics & X-ray data analysis

• Keith Arnaud, Randall Smith, Aneta Siemiginowska: "Handbook of X-ray Astronomy"

Observational astronomy & techniques

• Hale Bradt: "Astronomy Methods"
• George H. Rieke: "Measuring the Universe. A Multiwavelength Perspective"
• E.C. Sutton: ”Observational Astronomy. Techniques and Instrumentations"
• Kitchin C. R.: "Telescopes and Techniques"

Radio Astronomy

• J.J. Condon & S.M. Ransom: "Essential Radio Astronomy"
• G.B. Taylor, C.L. Carilli, R.A. Perley: "Synthesis imaging in radio astronomy II" (ASP Conf. Ser., Vol. 180)
• B.F. Burke: "An Introduction to radio astronomy"
• T.L. Wilson, K. Rohlfs, S. Huettemeister: "Tools of Radio Astronomy"
• A.R. Thompson, J.M. Moran, G.W. Swenson Jr.: "Interferometry and Synthesis in Radio Astronomy"

Others

• Specific guides and manuals to data reduction and analysis are uploaded on Virtuale.
• Readings/guidelines/manuals/lessons/tutorials/exercises for the high-energy module: https://indico.ict.inaf.it/event/3089
• https://science.nrao.edu/opportunities/courses/era/

Teaching methods

Teaching includes PowerPoint presentations and tutorials. Data analysis techniques and relevant tools are often presented in real time.

Students are strongly encouraged to participate in all group activities and are kindly requested to notify professors in advance of any absence.

In consideration of the type of activity and the adopted teaching methods (e.g., use of computer), the attendance of this training activity requires the prior participation of all students in the training modules 1 and 2 (formazione sulla sicurezza nei luoghi di studio) in e-learning mode [https://elearning-sicurezza.unibo.it].

Assessment methods

The exam is structured as follows:

• Radio/millimeter lab courses: each group will write a written report of about 20 pages (deadline around Jan. 10^th). Professors will evaluate the reports and provide comments to the students at the oral exam, which will consist of an individual interview on the main topics of the module.
• Optical/near-IR and high-energy lab modules: each group will prepare a PowerPoint presentation to be presented during the exam period. Each student will discuss a part of the PowerPoint presentation (10-15 min for each student; "who is presenting what" is decided by the professors).

Scores will depend on the quality of the presentations, on students' capability in hard work (in data analysis and interpretation) shown during the lab courses, and they participation in group activities.

To be more specific, each lab is assigned a score that contributes to the final grade. Upon completion of the three partial assessments, students may choose whether to accept the grade (based on a 30-scale) derived from the laboratory evaluations or to take a "new" final oral exam; in the latter case, the student effectively forfeits the grade assigned based on the three labs.

Final marks are assigned according to this scale:

• Limited (though sufficient) preparation and capability to explain the techniques adopted in data analysis, coupled with poor responses to questions: 18-22.
• Satisfactory though not complete preparation in technical and scientific issues: 23-25.
• Good/very good capability to explain the steps of data analysis and interpretation seen during the lessons and tutorials, and answer questions: 26-28.
• Excellent/outstanding ability to discuss and critically study the topics covered in the course, accompanied by correct overall linguistic expression: 29-30. Honors are awarded by the professors to the students who have shown full mastery of data analysis and physical interpretation of the results during the three lab courses and in the exam (report and PowerPoint presentations).

According to the policy of the Master in Astrophysics and Cosmology Course, students may not decline a grade more than twice. The grade from the last exam attempt is valid.

Students are strongly advised to have already attended and, possibly, taken the exams for he courses on AGN & SMBH and Stellar Evolution.

Regarding assessment, the use of generative Artificial Intelligence is not allowed unless explicitly authorised by the lecturer for specific parts of the project. Any use of generative AI must be declared by the student and must not replace the student’s own analysis, interpretation and critical discussion. Undeclared or unauthorised use of generative AI in the assessment constitutes a breach of academic integrity.

Students with learning disabilities or temporary or permanent disabilities: please contact the relevant University office promptly (https://site.unibo.it/studenti-con-disabilita-e-dsa/it). The office will advise students of possible adjustments, that will be submitted to the professor for approval 15 days in advance. He/she will evaluate their suitability also in relation to the academic objectives of the course.

Teaching tools

Powerpoint presentations, real-time data analysis, critical paper reading and discussion, and blackboard.

Office hours

See the website of Cristian Vignali

See the website of Alessio Mucciarelli

See the website of Paola Grandi

See the website of Rosita Paladino

See the website of Myriam Gitti