Stockholm university
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Giacomo BortoliniPhD student

About me

I am a PhD student in the Astronomy Department at Stockholm University, working with Prof. Göran Östlin and Prof. Angela Adamo. I specialize in the study of resolved stellar populations, star-formation histories, and chemical enrichment of dwarf galaxies within the nearby Universe. Alongside my research, I am deeply passionate about teaching and engaging in public outreach initiatives. My unique position as a pair-PhD involves a focus on higher education teaching in Astronomy alongside my daily research, made possible through a collaborative effort with the Department of Teaching and Learning. Learn more about my project Here!

Education:

  • PhD in Astronomy, Stockholm University, Sweden, 2022 - current
  • Master degree in Astronomy & astrophysics, Pisa University, Italy, 2019 - 2021
  • Bachelor degree in physics, Pisa University, Italy, 2015 - 2019

 

Take a look at some stunning images of galaxies I am studyng with the James Webb and Hubble Space Telescope: I Zw 18, NGC 4449. NGC 5474.

Teaching

Undergraduate education

  • Spring 2024 - Teaching assistant for the Observational Astrophysics I course (Master's level).
  • Fall 2024 - Teaching assistant for the Stellar Structure and Evolution course (Bachelor's level).

Research

I am part of several research teams and collaborations:

  • I Zw 18's JWST NIRCam & MIRI GTO (PI: Meixner)
  • JWST probes Feedback in Emerging extrAgalactic Star clusTers (FEAST, PI: Adamo)
  • HST Legacy Extragalactic UV Survey program (LEGUS, PI: Calzetti)

Publications

A selection from Stockholm University publication database

  • The spatially resolved star formation history of the dwarf spiral galaxy NGC 5474

    2024. Giacomo Bortolini (et al.). Monthly notices of the Royal Astronomical Society 527 (3), 5339-5355

    Article

    We study the resolved stellar populations and derive the star formation history of NGC 5474, a peculiar star-forming dwarf galaxy at a distance of ∼7 Mpc, using Hubble Space Telescope Advanced Camera for Surveys data from the Legacy Extragalactic UV Survey (LEGUS) programme. We apply an improved colour–magnitude diagram fitting technique based on the code SFERA and use the latest PARSEC–COLIBRI stellar models. Our results are the following. The off-centre bulge-like structure, suggested to constitute the bulge of the galaxy, is dominated by star formation (SF) activity initiated 14 Gyr ago and lasted at least up to 1 Gyr ago. Nevertheless, this component shows clear evidence of prolonged SF activity (lasting until ∼10 Myr ago). We estimate the total stellar mass of the bulge-like structure to be (5.0 ± 0.3) × 108 M⊙. Such a mass is consistent with published suggestions that this structure is in fact an independent system orbiting around and not within NGC 5474’s disc. The stellar overdensity located to the South–West of the bulge-like structure shows a significant SF event older than 1 Gyr, while it is characterized by two recent peaks of SF, around ∼10 and ∼100 Myr ago. In the last Gyr, the behaviour of the stellar disc is consistent with what is known in the literature as ‘gasping’. The synchronized burst at 10–35 Myr in all components might hint to the recent gravitational interaction between the stellar bulge-like structure and the disc of NGC 5474.

    Read more about The spatially resolved star formation history of the dwarf spiral galaxy NGC 5474

Show all publications by Giacomo Bortolini at Stockholm University

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