Bruno Merín
Astronomer

Research

Keywords

star formation, disk evolution, exoplanet, exoplanet formation

Word cloud of all my abstracts to date

>> The exoplanet revolution

Exoplanets

The study of how planets form boosted with the discovery of the first exoplanet by Michel Mayor and his collaborators around the star 51 Peg on 1995. Nowadays, it has grown to be a whole discipline by itself clearly separated from the general and long-standing star-forming studies.

>> The study of disk evolution on large samples of young stars


Habitable zone

The Spitzer Space Telescope, with its sensitive mid-infrared (5 - 35 micron) detectors, allowed to characterize the inner few Astronomical Units (AU) in an unprecedented sample of disks in the closest star-forming regions around the Sun. We have literally gone from samples of a few hundred objects to samples of a few thousands. Not only that, Spitzer has discovered a wild variety of inner disk architectures in all those young stars in nearby star-forming regions. In particular, it has confirmed the belief from previous observations that the age of the central star is not defining necessarily the evolutionary status of the disk, but that there are other physical variables involved in the process in a way that we still do not understand.

>> Herschel updates on disk evolution


Ophiuchus by Herschel

Herschel, with its senstive far-infrared cameras is complementing enormously the Spitzer data treasure very efficiently and promises to bring so much more information about the critical outer disks, from which we know still very little from previous data. See here a presentation I gave at ESA's InterDepartmental Science Workshop 2012 in Volendam summarizing our latest on-going projects with Herschel data as part of the Herschel Gould's Belt Key Programme.


Chamaeleon by Herschel at PPVI See here to see the poster we are presentating at the Protostars and Planets VI Conference at Heidelberg in 2013 summarizing our latest papers with Herschel data as part of the Herschel Gould's Belt Key Programme.

>>The study of transitional disks

The area of transitional disks (gas-rich disks around young stars with potential large inner gaps or holes, typically revealed by their Spectral Energy Distribution) continues to grow in interest. Now a few systems with gaps and possible planets inside of them have been found. And new interesting insights from the Herschel data suggests that they might not be the only path to form giant planets.

Selected recent works

Ribas et al. 2014 (Astronomy & Astrophysics): Disk evolution in the solar neighbourhood: Disk fractions from 1 to 100 Myrs

A large high-quality sample of protoplanetary and debris disks in most star-forming regions within 400 pc from the Sun with homogenized and quality controlled photometry allows us to compare disk fractions as a function of age and as a function of wavelength. We confirm the typical 10 Myr time-scale for disk dissipation and give evidence for inside out disk clearing during this phase.

Ribas et al. 2013 (Astronomy & Astrophysics): Identification of transitional disks in Chamaeleon with Herschel

We find higher fluxes at the PACS wavelengths in the sample of transitional disks than those of Class II objects. We show the Herschel 70 micron band to be an efficient tool for transitional disk identification. The systematic excess found at the PACS bands could be a result of the mechanism that produces the transitional phase, or an indication of different evolutionary paths for transitional disks and Class II sources.

Merin et al. (2010, ApJ) A Spitzer c2d Legacy Survey to Identify and Characterize Disks with Inner Dust Holes

Transitional disks homogeneously selected from the large Spitzer photometric sample of the "Cores 2 Disks" program (c2d) where observed with the Spitzer/IRS and among other things, the hole sizes were found to scale with the stellar masses.