The Astrophysical Journal Letters (Jan 2025)
First Mid-infrared Detection and Modeling of a Flare from Sgr A*
- Sebastiano D. von Fellenberg,
- Tamojeet Roychowdhury,
- Joseph M. Michail,
- Zach Sumners,
- Grace Sanger-Johnson,
- Giovanni G. Fazio,
- Daryl Haggard,
- Joseph L. Hora,
- Alexander Philippov,
- Bart Ripperda,
- Howard A. Smith,
- S. P. Willner,
- Gunther Witzel,
- Shuo Zhang,
- Eric E. Becklin,
- Geoffrey C. Bower,
- Sunil Chandra,
- Tuan Do,
- Macarena Garcia Marin,
- Mark A. Gurwell,
- Nicole M. Ford,
- Kazuhiro Hada,
- Sera Markoff,
- Mark R. Morris,
- Joey Neilsen,
- Nadeen B. Sabha,
- Braden Seefeldt-Gail
Affiliations
- Sebastiano D. von Fellenberg
- ORCiD
- Max Planck Institute for Radio Astronomy , Bonn 53121, Germany ; [email protected]
- Tamojeet Roychowdhury
- ORCiD
- Max Planck Institute for Radio Astronomy , Bonn 53121, Germany ; [email protected]; Department of Electrical Engineering, Indian Institute of Technology Bombay , Mumbai, 400076, India
- Joseph M. Michail
- ORCiD
- Center for Astrophysics ∣Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138-1516, USA
- Zach Sumners
- ORCiD
- McGill University , Montréal, QC H3A 0G4, Canada; Trottier Space Institute , 3550 Rue University, Montréal, QC H3A 2A7, Canada
- Grace Sanger-Johnson
- ORCiD
- Michigan State University , Department of Physics and Astronomy, East Lansing, MI 48824, USA
- Giovanni G. Fazio
- ORCiD
- Center for Astrophysics ∣Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138-1516, USA
- Daryl Haggard
- ORCiD
- McGill University , Montréal, QC H3A 0G4, Canada
- Joseph L. Hora
- ORCiD
- Center for Astrophysics ∣Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138-1516, USA
- Alexander Philippov
- ORCiD
- University of Maryland , College Park, MD 20742, USA
- Bart Ripperda
- ORCiD
- Canadian Institute for Theoretical Astrophysics, University of Toronto , 60 St. George Street, Toronto, ON M5S 3H8, Canada; David A. Dunlap Institute for Astronomy and Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada; Department of Physics, University of Toronto , 60 St. George Street, Toronto, ON M5S 1A7, Canada; Perimeter Institute for Theoretical Physics , 31 Caroline Street North, Waterloo, ON N2L 2Y5, Canada
- Howard A. Smith
- Center for Astrophysics ∣Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138-1516, USA
- S. P. Willner
- ORCiD
- Center for Astrophysics ∣Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138-1516, USA
- Gunther Witzel
- ORCiD
- Max Planck Institute for Radio Astronomy , Bonn 53121, Germany ; [email protected]
- Shuo Zhang
- ORCiD
- Michigan State University , Department of Physics and Astronomy, East Lansing, MI 48824, USA
- Eric E. Becklin
- Department of Physics & Astronomy, University of California , Los Angeles, 90095-1547, USA
- Geoffrey C. Bower
- ORCiD
- Academia Sinica Institute of Astronomy and Astrophysics , 645 N. A’ohoku Pl., Hilo, HI 96720, USA
- Sunil Chandra
- ORCiD
- Physical Research Laboratory , Navrangpura, Ahmedabad 380009, India
- Tuan Do
- ORCiD
- Department of Physics & Astronomy, University of California , Los Angeles, 90095-1547, USA
- Macarena Garcia Marin
- ORCiD
- European Space Agency (ESA), ESA Office, Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Mark A. Gurwell
- ORCiD
- Center for Astrophysics ∣Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138-1516, USA
- Nicole M. Ford
- ORCiD
- McGill University , Montréal, QC H3A 0G4, Canada; Trottier Space Institute , 3550 Rue University, Montréal, QC H3A 2A7, Canada
- Kazuhiro Hada
- ORCiD
- Graduate School of Science, Nagoya City University , Yamanohata 1, Mizuho-cho, Mizuho-ku, Nagoya 467-8501, Aichi, Japan; Mizusawa VLBI Observatory, National Astronomical Observatory of Japan , 2-12 Hoshigaoka, Mizusawa, Oshu, Iwate 023-0861, Japan
- Sera Markoff
- ORCiD
- Anton Pannekoek Institute for Astronomy, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The Netherlands; Gravitation and Astroparticle Physics Amsterdam Institute, University of Amsterdam , Science Park 904, 1098 XH 195 196 Amsterdam, The Netherlands
- Mark R. Morris
- ORCiD
- Department of Physics & Astronomy, University of California , Los Angeles, 90095-1547, USA
- Joey Neilsen
- ORCiD
- Villanova University Department of Physics , 800 E. Lancaster Ave., Villanova, PA 19085, USA
- Nadeen B. Sabha
- ORCiD
- Universität Innsbruck , Institut für Astro- und Teilchenphysik, Technikerstr. 25/8, 6020 Innsbruck, Austria
- Braden Seefeldt-Gail
- ORCiD
- Canadian Institute for Theoretical Astrophysics, University of Toronto , 60 St. George Street, Toronto, ON M5S 3H8, Canada; David A. Dunlap Institute for Astronomy and Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada
- DOI
- https://doi.org/10.3847/2041-8213/ada3d2
- Journal volume & issue
-
Vol. 979,
no. 1
p. L20
Abstract
The time-variable emission from the accretion flow of Sgr A*, the supermassive black hole at the Galactic center, has long been examined in the radio-to-millimeter, near-infrared (NIR), and X-ray regimes of the electromagnetic spectrum. However, until now, sensitivity and angular resolution have been insufficient in the crucial mid-infrared (MIR) regime. The MIRI instrument on JWST has changed that, and we report the first MIR detection of Sgr A*. The detection was during a flare that lasted about 40 minutes, a duration similar to NIR and X-ray flares, and the source's spectral index steepened as the flare ended. The steepening suggests that synchrotron cooling is an important process for Sgr A*'s variability and implies magnetic fields strengths ~ 40–70 G in the emission zone. Observations at 1.3 mm with the Submillimeter Array revealed a counterpart flare lagging the MIR flare by ≈10 minutes. The observations can be self-consistently explained as synchrotron radiation from a single population of gradually cooling high-energy electrons accelerated through (a combination of) magnetic reconnection and/or magnetized turbulence.
Keywords
