My main area of research is observational cosmology, in particular large-scale structure. I am heavily invested in the galaxy survey J-PAS , which is finally starting (in late-2022) after more than 10 years in the making. I worked on this new instrument from very early in the preliminary design, and have contributed significantly to its construction and to help define its scientific goals. I have been lead of working groups on Observational Cosmology, Photometric Redshifts, Large-Scale Structure and Quasars. Now I am the representative of the University of Sao Paulo on the J-PAS Collaboration Board.
With respect to my science interests, they are very diverse, but always have some connection with cosmology.
I have worked on statistical techniques for the exploration of the data in galaxy surveys, including Fisher matrix, optimal quadratic estimators, and the multi-tracer technique. One of the topics I have been interested in is how to implement the angular power spectrum over the past light cone using very thin redshift slices, and with an arbitrary number of tracers. We have recently clarified some of the issues in our papers Abramo, Ferri & Tashiro 2021, and Abramo et al. 2022 (see my list of publications on the link above).
Over the past few years I have become interested in applications of Machine Learning to astrophysics such as:
- Classification and regression in astronomical data sets [Queiroz et al. 2022, Rodrigues et al. 2022a, Rodrigues & Abramo 2021]
- The relation between galaxies and halos in hydro simulations such as IllustrisTNG, and models for "painting" galaxies onto N-body simulations [de Santi et al. 2022a, Rodrigues et al. 2022b]
- Cleaning up cosmological covariance matrices using auto-encoders [de Santi et al. 2022b]
Below is a list of the main grants that I have been a part of.
2022 - now
Exploiting two large astrophysical surveys: WEAVE-QSO and J-PAS
This is a 4-year bilateral project between Brazil (FAPESP) and France (Agence National de Recherche, ANR). I am the coordinator in Brazil, and the coordinator in France is Dr. Matthew Pieri. FAPESP is investing R$ 400k , and ANR is investing EUR 400k. WEAVE-QSO and J-PAS are two large astrophysical surveys active from 2022 to 2029, on two major observatories, supported by two international collaborations: WEAVE-QSO (European) and J-PAS (mainly Brazilian-Spanish). These two surveys are partners towards a common goal: cosmology and galaxy formation in the first half of the history of the universe using data of unprecedented quality and size. J-PAS does this by performing imaging in 56 colours and WEAVE-QSO follows this up with spectroscopy. The exploitation of this data presents a variety of challenges and opportunities that we seek to address through machine learning. In some cases, the first steps have been undertaken and preliminary results are already available, while in other cases the projects are in the cradle. The leads of these surveys propose to pool the expertise of the partners and bring together innovative methods for the fullest exploitation of our large common data set.
Participants: Raul Abramo (co-PI), Matthew Pieri (co-PI), Clotilde Naigle, Laerte Sodré Jr., Silvia Bonoli, Nina Hirata, Carolina Queiroz, Natália Rodrigues,
Funding agencies: Agence Nationale de la Recherche (ANR) and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
2020 - now
Science with the Brazilian robotic telescope (T80-South)
This is a Thematic Project funded by FAPESP (Proc. # 2019/26492-3) to support the telescope T80-South and the survey S-PLUS. S-PLUS is an astrophysical survey using 12 optical bands that is mapping thousands of square degrees of the sky from the Southern hemisphere. The data will be used for studies in galaxy evolution, clusters, and large-scale structure.
Participants: Claudia L. Mendes de Oliveira (PI), Raul Abramo (co-PI), Larte Sodré Jr. (co-PI), and many others
2018 - Now
Large-scale structure with the S-PLUS survey
This is a FAPESP regular grant (Proc. # 2018/04683-9) that was used to make preliminary studies on the viability of using S-PLUS data for cosmological applications.
Participants: Raul Abramo (PI)
2016 - 2017
New frontiers with galaxy surveys
FAPESP regular grant (Proc. # 2015/17199-0) to develop multi-tracer techniques for the study of large-scale structures.
Participants: Raul Abramo (PI)
2013 - 2017
The 3-D Universe: Astrophysics with Large Galaxy Surveys
Large galaxy surveys, either spectroscopic or photometric, are changing the landscape of Astronomy, since they are the best strategy to understand one of the most profound mysteries of contemporary cosmology: the nature of dark energy, the dominant component of the Universe, responsible for the acceleration of its expansion. From a cosmological perspective, galaxy redshift surveys are necessary to build 3-D maps of the galaxy distribution, which can then be used to estimate cosmological parameters through statistical studies of features imprinted in this distribution. The nature of dark energy is actually only one of the many scientific challenges that may be pursued with large surveys. In fact, as exemplified by the Sloan Digital Sky Survey (SDSS), which is regarded as the most productive project of all time in Astronomy, galaxy redshift or photometric surveys are powerful tools to study from asteroids in the Solar System to our own Galaxy, from galaxy evolution to the large-scale structures of the Universe. Indeed, large galaxy surveys are the most efficient way (if not the only one) to approach properly some of the big challenges of contemporary astronomy. At present, we are currently participating in the design of two new surveys: the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) and the Prime Focus Spectrograph for the Subaru Measurement of Images and Redshifts survey (PFS/SuMIRe ). Their potential is enormous from both the scientific and technological point of view. We already have graduate students and post-docs developing projects which have these surveys in mind. We also have strongparticipation in the development of instruments for these surveys: the panoramic CCD camera of J-PAS and the optical fiber sub-system for PFS/SuMIRe. The objective of this Thematic Project is twofold: i) to consolidate our scientific work with galaxy surveys, and ii) to obtain the funding in order to build the optical fiber sub-system of the PFS/SuM.
Participants: Laerte Sodré Jr. (PI), Raul Abramo (co-PI)
2010 - 2016
Galaxy evolution in the era of large surveys
Understanding how galaxies form and evolve remains one of the most significant problems in Astrophysics. To meet this challenge, our group has developed a technique of spectral synthesis, the empirical population synthesis, which allows to identify the dominant stellar populations of galaxies from the analysis of their spectra. This technique is suitable for the analysis of data produced by large surveys that cover large areas on the sky and that became essential tools to efficiently address several problems of contemporary astrophysics and cosmology. We have applied this technique to SDSS data, examining several properties of the galaxy population from studies involving nearly a million spectra. In this project we wish to extend our empirical synthesis approach to high redshift and actively participate in the design and implementation of two new spectroscopic and photometric surveys, J-PAS (Javalambre Physics of the Accelerating Universe Survey) and SuMIRe (Subaru Measurement of Images and Redshifts). The latter will be conducted with the aid of a new spectrograph, the PFS (Prime Focus Spectrograph), in which construction we were invited to participate. Our goal with this project is to obtain resources to enable the effective development of these activities and, especially, allow us to develop a preliminary study of a PFS sub-system called FOCCOS, involving the optical fibres and their connectors, which will provide the optical interface between the telescope and the spectrograph. Although the main objective of these two surveys is the study of dark energy, they must bring invaluable contributions to several areas of modern astronomy, including galaxy evolution..
Participants: Laerte Sodré Jr. (PI), Raul Abramo (co-PI), Claudia L. M. de Oliveira (co-PI)
2010 - Atual
J-PAS Astrophysical Survey
J-PAS (Javalambre Physics of the Accelerating Universe Astrophysical Survey) is a large-area medium-band optical survey that will map > 200 million galaxies, millions of quasars, thousands of Supernovas and many other types of solar system, galactic and extragalactic objects. I have been involved since the inception of the brazilian project to build the cameras for J-PAS. In Spain, J-PAS is supported by CSIC, CEFCA and the State Government of Aragón. In Brazil, J-PAS is supported by MCT/ON, FINEP, FAPESP (Proc. 2010/17649-1, 2011/18729-1 and 2012/00800-4) and FAPERJ..
Participants: Raul Abramo, Renato Dupke, Claudia L. M. de Oliveira, Laerte Sodré Jr., Narciso Benitez
2009 - 2016
The Instituto Nacional de Ciencia e Tecnologia em Astrofísica (National Institute of Science and Technology in Astrophysics, INCT-A) was a network of 144 researchers, whose mission was to insert Brazilian astronomy in the large international collaborations responsible for the new generation of telescopes and astronomical instruments. One of its legacies is the present Brazilian participation on the GMT (Giant Magellan Telescope), in which Brazil has a 4% stake. The project was funded by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) and FAPESP.
Principal Investigator: João Steiner