_version_ 1866929739954913280
author Shrestha, Manisha
DeSoto, Sabrina
Sand, David J.
Williams, G. Grant
Hoffman, Jennifer L.
Smith, Nathan
Smith, Paul S.
Milne, Peter
McCall, Callum
Maund, Justyn R.
Steele, Iain A
Wiersema, Klaas
Andrews, Jennifer E.
Bilinski, Christopher
Anche, Ramya M.
Bostroem, K. Azalee
Hosseinzadeh, Griffin
Pearson, Jeniveve
Leonard, Douglas C.
Hsu, Brian
Dong, Yize
Hoang, Emily
Janzen, Daryl
Jencson, Jacob E.
Jha, Saurabh W.
Lundquist, M. J.
Mehta, Darshana
Retamal, Nicolas Meza
Valenti, Stefano
Farah, Joseph
Howell, D. Andrew
McCully, Curtis
Newsome, Megan
Gonzalez, Estefania Padilla
Pellegrino, Craig
Terreran, Giacomo
author_facet Shrestha, Manisha
DeSoto, Sabrina
Sand, David J.
Williams, G. Grant
Hoffman, Jennifer L.
Smith, Nathan
Smith, Paul S.
Milne, Peter
McCall, Callum
Maund, Justyn R.
Steele, Iain A
Wiersema, Klaas
Andrews, Jennifer E.
Bilinski, Christopher
Anche, Ramya M.
Bostroem, K. Azalee
Hosseinzadeh, Griffin
Pearson, Jeniveve
Leonard, Douglas C.
Hsu, Brian
Dong, Yize
Hoang, Emily
Janzen, Daryl
Jencson, Jacob E.
Jha, Saurabh W.
Lundquist, M. J.
Mehta, Darshana
Retamal, Nicolas Meza
Valenti, Stefano
Farah, Joseph
Howell, D. Andrew
McCully, Curtis
Newsome, Megan
Gonzalez, Estefania Padilla
Pellegrino, Craig
Terreran, Giacomo
contents 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\pm 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 \pm 0.08 \% $ and $p_r =0.62 \pm 0.08 \% $) at +73.19 and +76.19 days when the light curve falls from the plateau. This is a phase where polarimetric data is sensitive to non-spherical 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 polarization is typical for Type II SNe, but the high level of polarization during the rising phase has only been observed in SN 2023ixf.
format Preprint
id arxiv_https___arxiv_org_abs_2410_08199
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Spectropolarimetry of SN 2023ixf reveals both circumstellar material and helium core to be aspherical
Shrestha, Manisha
DeSoto, Sabrina
Sand, David J.
Williams, G. Grant
Hoffman, Jennifer L.
Smith, Nathan
Smith, Paul S.
Milne, Peter
McCall, Callum
Maund, Justyn R.
Steele, Iain A
Wiersema, Klaas
Andrews, Jennifer E.
Bilinski, Christopher
Anche, Ramya M.
Bostroem, K. Azalee
Hosseinzadeh, Griffin
Pearson, Jeniveve
Leonard, Douglas C.
Hsu, Brian
Dong, Yize
Hoang, Emily
Janzen, Daryl
Jencson, Jacob E.
Jha, Saurabh W.
Lundquist, M. J.
Mehta, Darshana
Retamal, Nicolas Meza
Valenti, Stefano
Farah, Joseph
Howell, D. Andrew
McCully, Curtis
Newsome, Megan
Gonzalez, Estefania Padilla
Pellegrino, Craig
Terreran, Giacomo
High Energy Astrophysical Phenomena
Solar and Stellar Astrophysics
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\pm 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 \pm 0.08 \% $ and $p_r =0.62 \pm 0.08 \% $) at +73.19 and +76.19 days when the light curve falls from the plateau. This is a phase where polarimetric data is sensitive to non-spherical 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 polarization is typical for Type II SNe, but the high level of polarization during the rising phase has only been observed in SN 2023ixf.
title Spectropolarimetry of SN 2023ixf reveals both circumstellar material and helium core to be aspherical
topic High Energy Astrophysical Phenomena
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2410.08199