Category Archives: Uncategorized

Welcome Fabio: Future master of Sgr A*

Hello everyone!

My name is Fabio Cafardo and I just started my PhD in Astrophysics at IAG-USP under the supervision of Prof. Rodrigo Nemmen. I’m really happy and motivated by this new challenge in my life.

Astronomy has always been one of my passions. But, before getting my Astrophysics degree, I worked 10 years as a Business Administrator. This experience proved to me that it is very important to work with something which you really like. That’s what I am doing now!

The topic of my research project is the high-energy emission of the supermassive black hole in the center of Our Galaxy, called Sagittarius A*. It is a fascinating topic and I really hope to provide new insights into the high energy processes occurring there.

Welcome aboard, Fabio! We are happy you switched gears and are working with us.

Welcome, Ivan

This semester, we are welcoming a new member to the group: Ivan Almeida. Ivan just graduated with stellar grades at Physics USP and will begin his work as a grad student in the group. Below are a few words from him:

Hi all, my name is Ivan Carlos de Almeida, and I’m beginning my masters degree at IAG-USP under the supervision of professor Rodrigo Nemmen. I’m a physicist recently graduated at IF-USP.

While I were an undergrad student I’ve entered the “Black Hole group” as a student of “Iniciação Científica”. This was my first effective contact with astrophysics and it was really interesting!

Since childhood I’m curious about the night sky, stars and all the cosmos. Some years later I have developed interest in General Relativity. So Black Hole physics attracted me greatly.

In the current project I’ll do HD and MHD simulations of accretion around black holes. I’ll investigate the existence of winds and if these winds provide efficient feedback inside the galaxy.

Ivan was quite successful during his undergraduate research project: we are anticipating 2 papers resulting from his work. He got the prestigious FAPESP scholarship that will fund his graduate studies. A very small fraction of students obtain this scholarship.

Welcome aboard, Ivan!

Postdoctoral opportunity at our Black Hole Group

We have one or more postdoctoral positions available at our Black Hole Group. If you are interested in black hole (astro)physics (including theory/numerical simulations), AGNs and/or gamma-ray astronomy, you are welcome to apply for one of the positions.

More information about the position can be found in this detailed announcement or in the AAS Job Register (shorter) ad that will be published on Feb 1st. The deadline for applications is March 1st 2017.

One clarification though: this is a pre-application. The selected candidate(s) will be sponsored for a postdoctoral fellowship application to the Sao Paulo funding agency FAPESP. If approved, the position will be funded for two years with the possibility of extension for a third year contingent on performance. The salary is generous for Brazilian standards (it is the best paying postdoc salary in the country) and includes research/travel budget and relocation costs.


Congratulations to Raniere Menezes for his MsC degree

This is a late post, but I would like to congratulate Raniere Menezes who obtained his MsC on September. Raniere is the first graduate student who got his degree in the Black Hole Group. His master’s dissertation was on analyzing the gamma-ray variability of nearby AGNs observed with Fermi LAT.

Raniere’s work was very successful: we are writing a paper reporting the results of his analysis.  Stay tuned!


Welcome to IAG, Henrique

Let’s give a warm welcome to Henrique Gubolin, my new graduate student. Let’s hear from Henrique himself:

Hi! I’m Henrique Gubolin Torres, and I’m starting my masters degree under the supervision of Rodrigo Nemmen; I just graduated in physics at IF-USP and I already worked with galaxy clusters and simulations before.

In this new project, I’ll be doing black hole simulations with the help of some well known magnetohydrodynamic codes, of course. We will simulate gas around a non-spinning black hole (Schwarzschild) using a semi-Newtonian approach and Magnetohydrodynamic (MHD). I’m looking forward to this project and to my new graduate student life, so… here we go!

Buracos negros na Folha de SP

Neste Domingo foi publicado no jornal Folha de São Paulo uma reportagem sobre o meu trabalho de divulgação científica sobre buracos negros: veja seis maneiras de morrer com um buraco negro.

A reportagem é muito divertida e gostei especialmente das ilustrações: tragédia no espaço.

Para os curiosos que lerem esta postagem e a reportagem da Folha, seguem esclarecimentos sobre alguns ponto do texto:

  • As maneiras 1 e 2 de morrer no artigo são uma consequência do mesmo fenômeno físico, chamado de forças de maré e causado pelo comportamento da atração gravitacional a objetos astronômicos. Este tipo de fenômeno causa as marés na Terra.
  • Sobre a maneira 3: não se preocupem, o nosso Sol jamais se tornará um buraco negro porque ele é muito “magrinho”.
  • O telescópio de raios gama lançado pela NASA em 2008 chama-se Fermi, e não Glast. Glast era o nome da missão antes do lançamento. Eu estou envolvido com esta missão desde 2011.
  • Na reportagem: “analisando os diferentes espectros de radiação emitidos pelos buracos negros […]”. Na verdade, os buracos negros não emitem radiação em si, o que brilha é o turbilhão de gás caindo neles ou o gás que é expulso antes de cair.
  • A reportagem menciona que os buracos negros “ejetam mais energia do que absorvem — estão na verdade consumindo sua massa”. Nem todos os buracos negros se comportam desta maneira, mas uma pequena fração deles parece ter este comportamento bizarro, conforme eu e um colaborador temos pesquisado. Os artigos científicos relatando esta descoberta estão aqui e aqui.

Divirtam-se com estas tragédias espaciais!

Congrats to the newest PhD of IAG, Dr. Rocha da Silva

Congratulations to the newest PhD of our department, Dr. Gustavo Rocha da Silva! This week, Dr. Rocha da Silva successfully defended his thesis on MHD simulations of relativistic jets from gamma-ray bursts (GRBs), and demonstrated the importance of relativistic MHD in understanding the physics of GRB afterglows and the amplification of magnetic fields in the environment of such objects.

I was part of his PhD thesis committee — my first time in such a committee — and I enjoyed it very much.