Using data from the Gaia space observatory, we recently put together the largest collection of quasars in space and time, which allows us to map the structure of our universe.
Check out our paper led by Kate Storey-Fisher, as well as this press release by the European Space Agency.
Stars at the Edge of the Milky Way (01/2024)
In a recent paper led by MIT graduate student Xiaowei Ou we measure the rotation curve of the Milky Way using new data from the Gaia satellite, and find that stars at the outskirts of our galaxy travel significantly slower than expected. One possible explanation: the Milky Way might have less dark matter than we previously thought! Check out the press release here.
Star-shredding massive black holes (01/2024)
In a study led by MIT graduate student Megan Masterson we uncover new - previously hidden by dust - tidal disruption events, which are extreme instances when a nearby star is tidally drawn into a black hole and ripped to shreds. Here is a link to MIT's press release.
Top 10 Breakthroughs of the Year 2023
Physics World recently named our work within the EIGER collaboration on deciphering the physics in the early universe with JWST as one of the Top 10 Breakthroughs in Physics of 2023. Thank you for the honor!
Little Red Dots (08/2023)
One of the many exciting surprises revealed by JWST is the discovery of an abundant population of "little red dots" in the universe, which we believe are small and dusty, actively growing black holes. Check out this great article by Quanta Magazine about these mysterious sources.
Filaments of the Cosmic Web traced by JWST (07/2023)
Our first results from the ASPIRE survey using JWST NIRCam grism observations of quasar fields revealed a high-redshift quasar embedded in filaments of the cosmic web. In two papers led by Feige Wang and Jinyi Yang (University of Arizona) we found this abundance of galaxies in the filament, which is believed to evolve into a massive galaxy cluster at later times. Link to STScI's press release.
The elusive stellar light of quasar hosts (06/2023)
In our recent work led by Xuheng Ding (Kavli IPMU) published in Nature we discovered the long sought-after stellar light of the quasar host galaxies in the early universe. This allows us to finally study the co-evolution and interplay of galaxies and their growing supermassive black holes. Link to the press release.
The "First Light" conference at MIT (06/2023)
In June 2023 we welcomed more than 150 astronomers from around the world to MIT to present their work on the first results on the early Universe with JWST at the "First Light" conference. Science News wrote an article about the detection of the long sought-after stellar light of quasar host galaxies that was presented, and MIT News reported about the conference.
First results from the EIGER survey (06/2023)
Our first results using data from the James Webb Space Telescope are out! In papers led by Daichi Kashino (Nagoya University), Jorryt Matthee (ETH) and myself, we analyze deep NIRCam grism data from high-redshift quasar fields to explore the nature of galaxies that are responsible for the Epoch of Reionization, and study the properties of the most luminous, high-redshift quasar known to date. For details, have a look at STScI's press release, or this news article.
Exoplanet Destruction (05/2023)
In our recent article published in Nature by lead author Kishalay De (MIT) we report the first discovery of a star swallowing a planet. This serendipitous observation was made when analyzing data from NASA's NEOWISE survey for infrared transient events. Our observations offer a first glimpse of a planetary engulfment by a star, a fate that most likely awaits Earth in the deep future, about 5 billion years from now. For more information, have a look at MIT's press release, or for instance this news article in the New York Times.
Feeding a dormant black hole (04/2023)
In this recent paper led by Christos Panagiotou (MIT) we report a serendipitous discovery of a dust obscured tidal disruption event - a star being torn apart by a dormant supermassive black hole. Despite that it is the closest tidal disruption event observed to date located only 137 million light years from Earth in the center of the galaxy NGC 7392, it is only visible at infrared wavelengths and has been missed by optical surveys. Link to the press release.
Rapid Heating in the Early Universe (03/2023)
In a recent paper led by Rebecca Davies (Swinburne University) we found that the amount of warm carbon present in the intergalactic medium in the early universe suddenly increases by a factor of five over a very short period of time, of only 300 million years. These studies of the Reionisation Epoch are vital to understand when and how the first stars formed and began producing the elements that exist today. Link to the news article.
The end of Cosmic Dawn (06/2022)
In this work led by Sarah Bosman (Max Planck Institute for Astronomy) we determined the end of the Reionization Epoch - the last phase transition of our universe, when the intergalactic medium transitioned from a completely neutral state to the highly ionized state we observe today. We found that this epoch ended about 1.1 billion years after the Big Bang, much later than previously thought. Link to the press release.
Strong Winds hamper black hole growth (05/2022)
In this letter published in Nature and led by Manuela Bischetti (Astronomical Observatory of Trieste) we found ubiqutous highly energetic winds driven by quasars in the early universe. These winds have extreme velocities and prevent efficient gas accretion onto the quasars' supermassive black holes, thus slowing down the black hole growth. This further complicates the question of how supermassive black holes form and grow at very early cosmic times. Link to the news article.
The Most Distant Quasar Known (01/2021)
In this work led by Feige Wang (University of Arizona) we discovered the currently most distant quasar known to date at a redshift of z=7.64, only 670 Myr after the Big Bang. These high redshift quasars are crucial to study the formation and growth of supermassive black holes in the very early universe. Link to the press release.
Cool Gas Around Early Quasars (12/2019)
In this study led by Emanuele Farina (MPA) we found that a significant fraction of high-redshift quasars is surrounded by huge reservoirs of cold gas providing large amounts of fueling material for the black holes in the center of the quasars, which might explain their rapid growth in the early universe. Link to the press release.
The Milky Way’s Velocity Curve (12/2018)
Our recent study measures the circular velocity curve of the Milky Way out to large Galactocentric distances to unprecedented precision using luminous red giant stars as a tracer population. We find that the circular velocity curve declines gently but smoothly, indicating a smooth distribution of mass within the Milky Way. Link to the news article.
The Discovery of Young Quasars (05/2017)
In this work we present a new method to analyze the lifetime of high-redshift quasars, which is the time that galaxies shine as luminous quasars and during which the bulk of the black hole growth is believed to occur. Applying our method to a large sample of high-redshift quasar spectra we find a population of very young quasars, indicating lifetimes of only 10,000 years or less, which poses significant challenges on our current understanding of black hole growth. Link to the press release.
In our recent article published in Nature by lead author Kishalay De (MIT) we report the first discovery of a star swallowing a planet. This serendipitous observation was made when analyzing data from NASA's NEOWISE survey for infrared transient events. Our observations offer a first glimpse of a planetary engulfment by a star, a fate that most likely awaits Earth in the deep future, about 5 billion years from now. For more information, have a look at MIT's press release, or for instance this news article in the New York Times.