papers

Publications (23)

astro-ph.HE2025

The Non-Uniform Expansion of the Crab Nebula

T. Martin, D. Milisavljevic, T. Temim +4

We present extensive proper motion measurements of the Crab Nebula made from Canada-France-Hawaii Telescope MegaPrime/MegaCam images taken in 2007, 2016, and 2019. A total of 19974…

astro-ph.HE2026

Deciphering the "Green Monster" in Cassiopeia A: Puncturing and sculpting a heterogeneous circumstellar shell

S. Orlando, H. -T. Janka, D. Milisavljevic +6

JWST observations of Cassiopeia A have revealed the "Green Monster" (GM), a pockmarked region of shocked circumstellar medium (CSM) characterized by circular holes surrounded by br…

astro-ph.HE2025

JWST Observations of SN 2023ixf I: Completing the Early Multi-Wavelength Picture with Plateau-phase Spectroscopy

J. M. DerKacy, C. Ashall, E. Baron +46

We present and analyze panchromatic (0.35--14 m) spectroscopy of the Type II supernova 2023ixf, including near- and mid-infrared spectra obtained 33.6 days after explosion duri…

astro-ph.IM2023

Observations of the Planetary Nebula SMP LMC 058 with the JWST MIRI Medium Resolution Spectrometer

O. C. Jones, J. Álvarez-Márquez, G. C. Sloan +21

During the commissioning of {\em JWST}, the Medium-Resolution Spectrometer (MRS) on the Mid-Infrared Instrument (MIRI) observed the planetary nebula SMP LMC 058 in the Large Magell…

astro-ph2007

The Early Spectrophotometric Evolution of V1186 Scorpii (Nova Scorpii 2004 #1)

G. J. Schwarz, C. E. Woodward, M. F. Bode +19

We report optical photometry and optical through mid-infrared spectroscopy of the classical nova V1186 Sco. This slowly developing nova had an complex light curve with multiple sec…

astro-ph.GA2023

Nuclear high-ionisation outflow in the Compton-thick AGN NGC6552 as seen by the JWST mid-infrared instrument

J. Álvarez-Márquez, A. Labiano, P. Guillard +17

During the commissioning of the James Webb Space Telescope (JWST), the mid-infrared instrument (MIRI) observed NGC6552 with the MIRI Imager and the medium-resolution spectrograph (…

astro-ph.GA2023

ALMA Observations of Supernova Remnant N49 in the Large Magellanic Cloud. II. Non-LTE Analysis of Shock-heated Molecular Clouds

H. Sano, Y. Yamane, J. Th. van Loon +28

We present the first compelling evidence of shock-heated molecular clouds associated with the supernova remnant (SNR) N49 in the Large Magellanic Cloud (LMC). Using CO( =…

astro-ph.SR2025

JWST Observations of SN 2024ggi I: Interpretation and Model Comparison of the Type II Supernova 2024ggi at 55 days Past Explosion

E. Baron, C. Ashall, J. M. DerKacy +40

We present panchromatic 0.4-21 microns observations of the nearby (about 7.2 Mpc) Type II supernova 2024ggi, obtained during the plateau phase at about 55 d past explosion. Our dat…

astro-ph.HE2024

Ejecta, Rings, and Dust in SN 1987A with JWST MIRI/MRS

O. C. Jones, P. J. Kavanagh, M. J. Barlow +31

Supernova (SN) 1987A is the nearest supernova in 400 years. Using the {\em JWST} MIRI Medium Resolution Spectrograph, we spatially resolved the ejecta, equatorial ring (ER) a…

astro-ph.HE2024

Emission lines due to ionizing radiation from a compact object in the remnant of Supernova 1987A

C. Fransson, M. J. Barlow, P. J. Kavanagh +31

The nearby Supernova 1987A was accompanied by a burst of neutrino emission, which indicates that a compact object (a neutron star or black hole) was formed in the explosion. There…

astro-ph.SR2025

JWST Observations of SN 2024ggi II: NIRSpec Spectroscopy and CO Modeling at 285 and 385 Days Past the Explosion

T. Mera, C. Ashall, P. Hoeflich +20

We present James Webb Space Telescope (JWST) NIRSpec observations of SN~2024ggi, spanning wavelengths of 1.7--5.5 micron at +285.51 and +385.27 days post-explosion. These nebular s…

astro-ph.HE2025

Origin of holes and rings in the Green Monster of Cassiopeia A: Insights from 3D magnetohydrodynamic simulations

S. Orlando, H. -T. Janka, A. Wongwathanarat +10

[Abridged] Cassiopeia A (Cas A) provides a unique opportunity to study supernova (SN) dynamics and interactions with the circumstellar medium (CSM). Recent JWST observations reveal…

astro-ph.HE2018

ALMA observations of supernova remnant N49 in the LMC: I. Discovery of CO clumps associated with X-ray and radio continuum shells

Y. Yamane, H. Sano, J. Th. van Loon +24

N49 (LHA 120-N49) is a bright X-ray supernova remnant (SNR) in the Large Magellanic Cloud. We present new CO( = 1-0, 3-2), HI, and 1.4 GHz radio-continuum observations of…

astro-ph.HE2023

JWST NIRSpec observations of Supernova 1987A -- from the inner ejecta to the reverse shock

J. Larsson, C. Fransson, B. Sargent +23

We present initial results from JWST NIRSpec integral field unit observations of the nearby Supernova (SN) 1987A. The observations provide the first spatially-resolved spectroscopy…

astro-ph.SR2024

Deep JWST/NIRCam imaging of Supernova 1987A

Mikako Matsuura, M. Boyer, Richard G. Arendt +46

JWST/NIRCam obtained high angular-resolution (0.05-0.1''), deep near-infrared 1--5 micron imaging of Supernova (SN) 1987A taken 35 years after the explosion. In the NIRCam images,…

astro-ph.HE2025

The compact object and innermost ejecta of SN 1987A

J. Larsson, C. Fransson, P. J. Kavanagh +12

The first JWST observations of SN 1987A provided clear evidence that a compact object is ionizing the innermost ejecta. Here we analyze a second epoch of JWST NIRSpec and MIRI/MRS…

astro-ph.SR2024

JWST MIRI Imager Observations of Supernova SN 1987A

P. Bouchet, R. Gastaud, A. Coulais +31

There exist very few mid-infrared (IR) observations of supernovae (SNe) in general. Therefore, SN 1987A, the closest visible SN in 400 years, gives us the opportunity to explore th…

astro-ph.HE2016

Radio Polarization Observations of the Snail: A Crushed Pulsar Wind Nebula in G327.1-1.1 with a Highly Ordered Magnetic Field

Y. K. Ma, C. -Y. Ng, N. Bucciantini +3

Pulsar wind nebulae (PWNe) are suggested to be acceleration sites of cosmic rays in the Galaxy. While the magnetic field plays an important role in the acceleration process, previo…

astro-ph.SR2025

JWST Observations of SN 2023ixf II: The Panchromatic Evolution Between 250 and 720 Days After the Explosion

K. Medler, C. Ashall, P. Hoeflich +60

We present the nebular phase spectroscopic and photometric observations of the nearby hydrogen-rich core-collapse supernova (CC-SN) 2023ixf, obtained through our JWST programs. The…

astro-ph.GA2024

Shockingly Bright Warm Carbon Monoxide Molecular Features in the Supernova Remnant Cassiopeia A Revealed by JWST

J. Rho, S. -H. Park, R. Arendt +36

We present JWST NIRCam (F356W and F444W filters) and MIRI (F770W) images and NIRSpec- IFU spectroscopy of the young supernova remnant Cassiopeia A (Cas A). We obtained the data as…

astro-ph.HE2018

Investigating the Structure of Vela X

P. Slane, I. Lovchinsky, C. Kolb +9

Vela X is the prototypical example of a pulsar wind nebula whose morphology and detailed structure have been affected by the interaction with the reverse shock of its host supernov…

astro-ph.HE2026

The evolution of the mid-infrared spectrum of SN 1987A observed with the JWST/MIRI-MRS

P. J. Kavanagh, M. J. Barlow, C. Fransson +19

Supernova (SN) 1987A provides a unique laboratory for investigating many aspects of SN physics and evolution. An observation at Day 12927 (35.4 yr) since the explosion with the Mid…

astro-ph.HE2025

Filamentary Ejecta Network in Cassiopeia~A Reveals Fingerprints of the Supernova Explosion Mechanism

S. Orlando, H. -T. Janka, A. Wongwathanarat +7

[Abridged] Recent JWST observations have revealed an intricate filamentary network of unshocked ejecta in the young supernova remnant (SNR) Cassiopeia A (Cas A), offering new insig…