Matteo Messa


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Works at Department of Astronomy
Telephone 08-553 785 42
Visiting address Roslagstullsbacken 21, C 6 & D 6
Room C6:3015
Postal address Institutionen för astronomi 10691 Stockholm

About me

I am working as PhD student in the galaxy group of the astronomy department at Stockholm university, under the supervision of Dr. Angela Adamo and Prof. Göran Östlin.

My research has been focused on the study of star formation at the scales of young star clusters and clumps, both in local main sequence and in starburst galaxies. Within the LEGUS HST treasury program (, I analyzed young clusters in nearby galaxies. Different environments inside galaxies are used to understand how cluster formation is affected by the local environment. 
In a similar way I am analyzing star-forming clumps in a sample of nearby analogs of high redshift galaxies. In such galaxies the clumps dominate the UV brightness and strongly affect their environment via feedback. I am studying the effect of clumpy star formation on the galaxies at scales down to 10 pc, fundamental to shade light on the star formation process and the leaking of UV photons at high redshifts. 

In my research, I am mainly interested in the star formation process, in how it is affected by the galaxy environment and how in turn it affects the environment via feedback. Star formation is the major mechanism of baryonic matter transformation in the universe and it shapes the galaxies as we see them. The evolution of the star formation process with redshift is essential to understand how different environments regulate the star formation as well as to understand how galaxies evolve with time. Star-forming clumps and young stellar cluster, being one of the main products of star formation, are particularly suited for this kind of studies. They represent the key to link different scales of star formation, from stellar-scale processes to the galactic (and even circum-galactic) scale.


A selection from Stockholm University publication database
  • 2018. Matteo Messa (et al.). Monthly notices of the Royal Astronomical Society 477 (2), 1670-1694

    It has recently been established that the properties of young star clusters (YSCs) can vary as a function of the galactic environment in which they are found. We use the cluster catalogue produced by the Legacy ExtragalacticUVSurvey (LEGUS) collaboration to investigate cluster properties in the spiral galaxy M51. We analyse the cluster population as a function of galactocentric distance and in arm and inter-arm regions. The cluster mass function exhibits a similar shape at all radial bins, described by a power law with a slope close to -2 and an exponential truncation around 10(5) M-circle dot. While the mass functions of the YSCs in the spiral arm and inter-arm regions have similar truncation masses, the inter-arm region mass function has a significantly steeper slope than the one in the arm region, a trend that is also observed in the giant molecular cloud mass function and predicted by simulations. The age distribution of clusters is dependent on the region considered, and is consistent with rapid disruption only in dense regions, while little disruption is observed at large galactocentric distances and in the inter-arm region. The fraction of stars forming in clusters does not show radial variations, despite the drop in the H-2 surface density measured as a function of galactocentric distance. We suggest that the higher disruption rate observed in the inner part of the galaxy is likely at the origin of the observed flat cluster formation efficiency radial profile.

  • 2018. Matteo Messa (et al.). Monthly notices of the Royal Astronomical Society 473 (1), 996-1018

    Recently acquired WFC3 UV (F275W and F336W) imaging mosaics under the Legacy Extragalactic UV Survey (LEGUS), combined with archival ACS data of M51, are used to study the young star cluster (YSC) population of this interacting system. Our newly extracted source catalogue contains 2834 cluster candidates, morphologically classified to be compact and uniform in colour, for which ages, masses and extinction are derived. In this first work we study the main properties of the YSC population of the whole galaxy, considering a mass-limited sample. Both luminosity and mass functions follow a power-law shape with slope -2, but at high luminosities and masses a dearth of sources is observed. The analysis of the mass function suggests that it is best fitted by a Schechter function with slope -2 and a truncation mass at 1.00 +/- 0.12 x 10(5) M-circle dot . Through Monte Carlo simulations, we confirm this result and link the shape of the luminosity function to the presence of a truncation in the mass function. A mass limited age function analysis, between 10 and 200 Myr, suggests that the cluster population is undergoing only moderate disruption. We observe little variation in the shape of the mass function at masses above 1 x 10(4) M-circle dot over this age range. The fraction of star formation happening in the form of bound clusters in M51 is similar to 20 per cent in the age range 10-100 Myr and little variation is observed over the whole range from 1 to 200 Myr.

Show all publications by Matteo Messa at Stockholm University

Last updated: October 4, 2018

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