The Astrophysical Journal Letters (Jan 2025)
Spectropolarimetry of SN 2023ixf Reveals Both Circumstellar Material and an Aspherical Helium Core
- Manisha Shrestha,
- Sabrina DeSoto,
- David J. Sand,
- G. Grant Williams,
- Jennifer L. Hoffman,
- Paul S. Smith,
- Callum McCall,
- Justyn R. Maund,
- Iain A. Steele,
- Klaas Wiersema,
- Jennifer E. Andrews,
- Nathan Smith,
- Christopher Bilinski,
- Peter Milne,
- Ramya M. Anche,
- K. Azalee Bostroem,
- Griffin Hosseinzadeh,
- Jeniveve Pearson,
- Douglas C. Leonard,
- Brian Hsu,
- Yize Dong,
- Emily Hoang,
- Daryl Janzen,
- Jacob E. Jencson,
- Saurabh W. Jha,
- M. J. Lundquist,
- Darshana Mehta,
- Nicolás Meza Retamal,
- Stefano Valenti,
- Joseph Farah,
- D. Andrew Howell,
- Curtis McCully,
- Megan Newsome,
- Estefania Padilla Gonzalez,
- Craig Pellegrino,
- Giacomo Terreran
Affiliations
- Manisha Shrestha
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- Sabrina DeSoto
- ORCiD
- Department of Physics & Astronomy, University of Denver , 2112 East Wesley Avenue, Denver, CO 80208, USA
- David J. Sand
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- G. Grant Williams
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]; MMT Observatory, PO Box 210065, University of Arizona , Tucson, AZ 85721-0065, USA
- Jennifer L. Hoffman
- ORCiD
- Department of Physics & Astronomy, University of Denver , 2112 East Wesley Avenue, Denver, CO 80208, USA
- Paul S. Smith
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- Callum McCall
- ORCiD
- Astrophysics Research Institute, Liverpool John Moores University , 146 Brownlow Hill, Liverpool L3 5RF, UK
- Justyn R. Maund
- ORCiD
- Department of Physics, Royal Holloway, University of London , Egham, TW20 0EX, UK
- Iain A. Steele
- ORCiD
- Astrophysics Research Institute, Liverpool John Moores University , 146 Brownlow Hill, Liverpool L3 5RF, UK
- Klaas Wiersema
- ORCiD
- Centre for Astrophysics Research, University of Hertfordshire , Hatfield, AL10 9AB, UK
- Jennifer E. Andrews
- ORCiD
- Gemini Observatory , 670 North A‘ohoku Place, Hilo, HI 96720-2700, USA
- Nathan Smith
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- Christopher Bilinski
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- Peter Milne
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- Ramya M. Anche
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- K. Azalee Bostroem
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- Griffin Hosseinzadeh
- ORCiD
- Department of Astronomy & Astrophysics, University of California, San Diego , 9500 Gilman Drive, MC 0424, La Jolla, CA 92093-0424, USA
- Jeniveve Pearson
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- Douglas C. Leonard
- ORCiD
- Department of Astronomy, San Diego State University , San Diego, CA 92182-1221, USA
- Brian Hsu
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA ; [email protected]
- Yize Dong
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138-1516, USA
- Emily Hoang
- ORCiD
- Department of Physics and Astronomy, University of California, Davis , 1 Shields Avenue, Davis, CA 95616-5270, USA
- Daryl Janzen
- ORCiD
- Department of Physics & Engineering Physics, University of Saskatchewan , 116 Science Place, Saskatoon, SK S7N 5E2, Canada
- Jacob E. Jencson
- ORCiD
- IPAC , Mail Code 100-22, Caltech, 1200 E. California Blvd., Pasadena, CA 91125, USA
- Saurabh W. Jha
- ORCiD
- Department of Physics and Astronomy, Rutgers, the State University of New Jersey , 136 Frelinghuysen Road, Piscataway, NJ 08854-8019, USA
- M. J. Lundquist
- ORCiD
- W. M. Keck Observatory , 65-1120 Māmalahoa Highway, Kamuela, HI 96743-8431, USA
- Darshana Mehta
- Department of Physics and Astronomy, University of California, Davis , 1 Shields Avenue, Davis, CA 95616-5270, USA
- Nicolás Meza Retamal
- ORCiD
- Department of Physics and Astronomy, University of California, Davis , 1 Shields Avenue, Davis, CA 95616-5270, USA
- Stefano Valenti
- ORCiD
- Department of Physics and Astronomy, University of California, Davis , 1 Shields Avenue, Davis, CA 95616-5270, USA
- Joseph Farah
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA; Department of Physics, University of California, Santa Barbara , Broida Hall, Santa Barbara, CA 93106-9530, USA
- D. Andrew Howell
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA; Department of Physics, University of California, Santa Barbara , Broida Hall, Santa Barbara, CA 93106-9530, USA
- Curtis McCully
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA
- Megan Newsome
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA; Department of Physics, University of California, Santa Barbara , Broida Hall, Santa Barbara, CA 93106-9530, USA
- Estefania Padilla Gonzalez
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA; Department of Physics, University of California, Santa Barbara , Broida Hall, Santa Barbara, CA 93106-9530, USA
- Craig Pellegrino
- ORCiD
- Department of Astronomy, University of Virginia , Charlottesville, VA 22904, USA
- Giacomo Terreran
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA; Department of Physics, University of California, Santa Barbara , Broida Hall, Santa Barbara, CA 93106-9530, USA
- DOI
- https://doi.org/10.3847/2041-8213/adbb63
- Journal volume & issue
-
Vol. 982,
no. 1
p. L32
Abstract
We present multi-epoch optical spectropolarimetric and imaging polarimetric observations of the nearby Type II supernova (SN) 2023ixf discovered in M101 at a distance of 6.85 Mpc. The first imaging polarimetric observations were taken +2.33 days (60085.08 MJD) after the explosion, while the last imaging polarimetric data points (+73.19 and +76.19 days) were acquired after the fall from the light-curve plateau. At +2.33 days there is strong evidence of circumstellar material (CSM) interaction in the spectra and the light curve. A significant level of intrinsic polarization p _r = 1.02% ± 0.07% is seen during this phase, which indicates that this CSM is aspherical. We find that the polarization evolves with time toward the interstellar polarization level during the photospheric phase, which suggests that the recombination photosphere is spherically symmetric. There is a jump in polarization ( p _r = 0.45% ± 0.08% and p _r = 0.62% ± 0.08%) at +73.19 and +76.19 days when the light curve falls from the plateau. This is a phase where polarimetric data are sensitive to nonspherical inner ejecta or a decrease in optical depth into the single-scattering regime. We also present spectropolarimetric data that reveal line (de)polarization during most of the observed epochs. In addition, at +14.50 days we see an “inverse P Cygni” profile in the H and He line polarization, which clearly indicates the presence of asymmetrically distributed material overlying the photosphere. The overall temporal evolution of the polarization is typical for Type II SNe, but the high level of polarization during the rising phase has only been observed in SN 2023ixf.
Keywords
- Core-collapse supernovae
- Type II supernovae
- Red supergiant stars
- Stellar mass loss
- Circumstellar matter
- Spectropolarimetry
