Pedro Henrique Cezar Event, News

Acompanhamos o anúncio da primeira imagem de Sgr A*

O dia 12 de Maio foi cheio de emoção em nosso grupo. Foi revelada ao mundo pela colaboração Event Horizon Telescope (EHT) a primeira imagem de Sgr A*, o buraco negro supermassivo que habita o centro da Via Láctea. É a primeira detecção direta do buraco negro da nossa galáxia. Esse resultado em conjunto com a imagem do buraco negro supermassivo M87*, divulgado pela mesma colaboração em 2019, impacta ao confirmar diretamente a existência de buracos negros no centro de galáxias e abre portas para testar a física nesses ambientes extremos.

A primeira imagem da sombra de Sgr A*, o buraco negro supermassivo da Via Láctea. A imagem foi produzida pela colaboração do Event Horizon Telescope (EHT). Crédito: EHT Collaboration.

Para acompanhar o anúncio em tempo real divulgado pela National Science Foundation (NSF) o Black Hole Group organizou um evento no Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG) da USP. O evento contou com algumas palavras introdutórias do Prof. Rodrigo Nemmen, seguida por uma apresentação acerca de Sgr A* dada pelo mestrando Lucas Siconato, que estuda com o telescópio espacial Fermi a região de Sgr A*. Em seguida, o Prof. Nemmen deu uma visão geral sobre o Event Horizon Telescope e as expectativas do que seria anunciado.

“Sagitário A* é um buraco negro supermassivo que a gente pode chamar de nosso.”

Lucas Siconato, mestrando do grupo que trabalha com o telescópio espacial Fermi a região de Sgr A* em raios-gama.
Grupo reunido em comemoração a imagem de Sgr A*. Da esquerda para direita: Raniere de Menezes, Ivan Almeida, Pedro Motta, Catarina Aydar, Roberta Duarte, Douglas Carlos, Rodrigo Nemmen, Matheus Branco e Lucas Siconato.

A Repercussão do evento contou com cobertura da mídia nacional. Durante as entrevistas, ficou em destaque a pesquisa da doutoranda Roberta Duarte, cujo trabalho é pioneiro ao aplicar inteligência artificial para simular buracos negros interagindo com a sua vizinhança.

A doutoranda do grupo Roberta Duarte concedendo entrevista ao Jornal Nacional. A sua pesquisa pioneria que alia inteligência artificial a buracos negros ficou em destaque.
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Group at IAU GALFEED Symposium

On the week of March 2nd to 6th, the Black Hole Group attended the IAU Symposium 359: Galaxy Evolution and Feedback Across Different Environments, or simply the GALFEED symposium. The event occurred at the beautiful setting of Bento Gonçalves in the south of Brasil. This is the wine region of the country, which specializes in the merlot variety.

This was an incredible event which led to many fruitful interactions between the group members and the galaxy evolution community. Beginning on March 2nd, Fabio and Raniere gave poster flash talks where they had the daunting challenge of summarizing their posters in only one minute. Not so easy, but they did a great job!

  • Queue of students waiting to present their work
  • Fabio Cafardo presenting his PhD work on Sgr A*
  • Raniere de Menezes presenting his work on low-luminosity AGNs

On Tuesday, it was Ivan and Gustavo’s turn to face the one-minute-present-all-your-research challenge. And again, it went fantastic!

  • Gustavo Soares talking about blazars and their spins
  • Ivan Almeida presenting his numerical simulations of black hole winds at low Eddington ratios

On Wednesday, we surprised Fabio with a surprise birthday party: it was his 40th birthday! There was cake and presents!

Fabio’s birthday. From left to right: Raniere, Gustavo, Fabio, Ivan, Rodrigo and Roderik

On Thursday, it was Rodrigo’s turn. He surprised the audience by beginning hist talk about spin estimates for M87*…

Rodrigo begins his talk on the spin of M87*. Certainly not the best of pictures…

… and then switching gears to talk about the first AI simulation of a black hole—the work of graduate student Roberta Pereira.

The first quarter of 2020 was very bright and productive for the group, despite the worrying news with COVID-19 all over the world.

Thanks to the IAU and FAPESP for funding our group’s attendance to this meeting.

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Attending the biggest event of AI and Machine Learning in Latin America: Khipu

From November 10th to November 15th, Khipu happened in Montevideo, Uruguay. Khipu was the best biggest event of artificial intelligence and machine learning in Latin America. The speakers of this event are all AI leaders in their fields and big companies such as Google, Deepmind, Apple and Facebook were sponsoring the event. The competition to be in one of the 200 participants of this event was highly competitive. It was one in a lifetime experience that I will try to sum up here. 

On the very first day, they welcomed us with a small lecture about motivation in AI fields and with a toast event. In this toast event, I met Nando de Freitas (Principal Scientist at Deepmind and of the main speakers there) and Cho Kyunghyun (Research at Facebook AI and NYU Professor), we talked about my project, about the event and about Brazil! They were really nice and friendly to me and my friend.

All of the lectures were interesting but I will give special attention to some of them: Ian Goodfellow talking about GANs, Yoshua Bengio talking about Perspectives in AI, Nando de Freitas talking about Reinforcement Learning, Cho Kyunghyun talking about Recurrent Neural Networks and Jeff Dean closing the event with an amazing talk about the challenges in AI. All the lectures are available here: http://tv.vera.com.uy/buscar?search=Khipu

Another important lecture was “How To Write a Good Paper”. So important and very helpful ideas!

Another highlight in this event was Nando de Freitas talking about my project with me when he visited my poster and commenting about my project in his lecture. It was a really special moment for sure. He even posted in Twitter and retweet my tweet talking about the project. I received a supportive comment from Cho Kyunghyun as well.

It is impossible to talk about Khipu without talking about Jeff Dean (GoogleAI leader and one of Tensorflow creators). I talk with him for a few minutes in a coffee break, he is also very friendly and we talked about my project and about GoogleAI opportunities. In his awesome lecture about challenges in AI, he also comments about my project and I found that one of the biggest highlights in the week. I took a picture with him and posted on Twitter, he commented.

I even met some amazing people from DeepMind and GoogleAI there, they gave me a lot of advice and talked about the life in DeepMind and in GoogleAI. I even met Feryal Behbahani from DeepMind and Women in ML and Oriol Vinyals from DeepMind (main AlphaStar researcher)

This event was so important with so many big names in AI. I am very thankful for Khipu because this event because I have so many opportunities now and also big thank you because they paid all the expenses with travel and accommodation. I really look forward to Khipu 2020! It is a really life changing experience.  

Credits of pictures: @Khipu_AI

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Massive presence of the group at the Brazilian Astronomical Society Meeting

The Black Hole Group had a massive presence at the 43th meeting of the Brazilian Astronomical Society—Sociedade Astronômica Brasileira, SAB.

After Marta Volonteri’s review talk on the cosmic evolution of massive black holes, Fabio gave a presentation about the current status of his analysis of Fermi LAT observations of the Galactic Center—we are finishing the first paper of the series which should be submitted very soon.

Fabio Cafardo’s talk at the 43th SAB meeting.

After Fabio’s talk, we’ve had Ivan’s talk on his numerical hydrodynamical simulations of radiatively inefficient accretion flows and their winds.

Ivan Almeida’s talk at the 43th SAB meeting.

Roberta Pereira presented her poster on applying deep learning to predict the future of accreting black holes, which are an extreme example of spatiotemporally chaotic systems.

Finally, Gustavo won one of the best poster prizes at the meeting, and was awarded a talk at the meeting. Wait, is that an award? 🙂

Gustavo Soares’s talk at the 43th SAB meeting.

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Group taught course at ICTP-SAIFR high-energy astrophysics school

From August 8 to 13, our group taught two courses at the high-energy astrophysics school at ICTP-SAIFR. The first was taught by myself and gave a broad overview of the active galactic nuclei phenomenon, including blazars. The second course was about Fermi LAT observations and taught by Fabio Cafardo, a PhD student in the group who is working of gamma-ray astronomy.

Fabios’s lecture also included a fun hands-on tutorial, teaching the students to analyze gamma-ray observations of the blazar TXS 0506+056. This is the famous blazar which was observed to emit gamma-rays flares and produce a high-energy neutrino at the same time: the second source ever observed in multimessenger astronomy. The first was the neutron star collision observed in gravitational waves with LIGO/Virgo and electromagnetic radiation.

Here is the official abstract for the AGNs and blazars course:

I will give a broad overview of the phenomenology and theory behind the active galactic nuclei (AGN) phenomenon. I will give a particular emphasis on systems which produce relativistic jets such as blazars, given their importance in multimessenger astronomy. I will cover the basic physics of gas accretion and jet production from Kerr black holes. I will also give an overview of the electromagnetic signature from AGNs and blazars, focusing on their gamma-ray emission commonly observed with the Fermi, HESS, MAGIC telescopes, and in the future CTA.

And here is the official description of the Fermi LAT tutorial:

The Fermi Gamma-ray Observatory has revolutionized our understanding of the high-energy universe. Over the last 10 years, the Fermi Large Area Telescope has been observing the entire sky from space every three hours in the 100 MeV to 500 GeV energy range. In this lab activity, We will give a short presentation highlighting the main results and importance of the Fermi Telescope—particularly for blazar and dark matter indirect searches. The talk will be followed by a hands-on tutorial where the students will get familiar with the analysis of space-based gamma-ray observations. 

Here is the material that we covered:

  1. Active galactic nuclei and blazars (Nemmen). Two lectures, 3 hours. Lecture 1, lecture 2
  2. Fermi LAT (Cafardo). Lecture, 1 hour
  3. Fermi LAT hands-on session (Cafardo). 1.5 hours

If you want to run tutorial #3 at home, you can download all the material from the third lecture and perform the analysis without needing to install a lot of additional software. We prepared the tutorial such that you only need to install one software and run an install script.

I suggested some reading for the students interested in diving deeper into AGN physics:

  1. Physical processes in active galactic nuclei, Blandford (cf. from p171 onwards in the PDF). Even though this is a quite dated treatment—from 20 years ago!—and a lot has changed since then, this paper does a great job in summarising the basic physics of the AGN phenomenon. 
  2. Relativistic jets in active galactic nuclei, arXiv:1812.06025. Up-to-date review about AGN jets
  3. Foundations of black hole accretion disk theory. Focuses on black hole accretion, with a general relativistic treatment

Here are some pictures from the event.

Rodrigo Nemmen and Pasquale Blasi tackling questions from the audience. Credit: Ivan Almeida.
Fabio Cafardo teaching the Fermi LAT hands-on tutorial. Credit: Rodrigo.
Another shot of Fabio during his course. Credit: Ivan.
Some of the diverse audience at the school. Credit: Fabio.

Thanks Fabio Iocco for the invitation. This was fun!

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Fermi Symposium + Collaboration meeting + NASA GSFC visit

The PhD students of the group working on gamma-ray observations—Fabio and Raniere—spent the last two weeks in Washington DC and surroundings. They went to the Fermi LAT Collaboration meeting at George Washington University, where they interacted with gamma-ray astronomers in the Fermi Collaboration. Raniere presented his ongoing analysis of the gamma-ray emission of a population of nearby AGNs.

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Raniere de Menezes presenting his work on low-luminosity AGNs at the Fermi LAT Collaboration Meeting, Washington DC.

Following the Collaboration meeting, the students presented their research at the Fermi Symposium in Baltimore. Raniere presented a poster about his work on the pulsar populations in Milky Way globular clusters—which is about to be submitted for publication—while Fabio gave a talk describing his analysis of the gamma-ray emission from the Galactic Center on constraints on Sgr A* physics.

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Fabio Cafardo presenting his work on the gamma-ray emission of Sgr A* at the Fermi Symposium, Baltimore.

After the symposium, Fabio and Raniere spent a couple of days visiting NASA Goddard Space Flight Center to discuss their research with GSFC scientists.

Their visit was possible thanks to NASA funds, grant xxxxxx.

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Course on General Relativistic Magnetohydrodynamics by Yosuke Mizuno

Yosuke Mizuno (Goethe University, Frankfurt) taught an advanced course on general relativistic magnetohydrodynamics on August 13-17 at our institute. General relativistic magnetohydrodynamics—or GRMHD—is an essential tool to model high-energy astrophysical phenomena such as accreting black holes and relativistic jets—precisely the type of phenomena that our group loves and cherishes. This course was very useful for everybody in the group. 

The slides are available on this website.

IMG_2194
Yosuke Mizuno lecturing about GRMHD at IAG USP. Credit: Rodrigo Nemmen.

His visit was supported by FAPESP grant 2013/10559-5.

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Group will teach analysis of Fermi LAT data in dark matter school

On the final week of July, members of our research group (Fabio, Raniere & Rodrigo) will be teaching a lesson on the analysis of Fermi LAT gamma-ray observations in the School and Workshop on Dark Matter and Neutrino Detection at ICTP-SAIFR. In this hands-on activity, we will teach how to analyze gamma-ray data for a dwarf galaxy, do a simple estimate of the dark matter cross section and reproduce the analysis described in Ackermann et al. (2015).

It will be fun!