UHECR mass composition from anisotropy of their arrival directions with the Telescope Array SD

the Telescope Array Collaboration

UHECR mass composition from anisotropy of their arrival directions with the Telescope Array SD

the Telescope Array Collaboration

Research output: Contribution to journal › Conference article › peer-review

Abstract

We propose a new method for the estimation of ultra-high energy cosmic ray (UHECR) mass composition from a distribution of their arrival directions. The method employs a test statistic (TS) based on a characteristic deflection of UHECR events with respect to the distribution of luminous matter in the local Universe modeled with a flux-weighed 2MRS catalog. Making realistic simulations of the mock UHECR sets, we show that this TS is robust to the presence of galactic and non-extreme extra-galactic magnetic fields and sensitive to the mass composition of events in a set. We apply the method to Telescope Array surface detector data for 11 years and derive new independent constraints on fraction of protons and iron in p-Fe mix at E > 10 EeV. At 10 < E < 100 EeV the data favors increase of allowed proton fraction and decrease of allowed iron fraction, while at E > 100 EeV — pure iron or even more massive composition. This result is in tension with Auger composition model inferred from spectrum–X_max fit at 2.7σ (2.0σ) for PT’11 (JF’12) regular GMF model.

Original language	English
Article number	294
Journal	Proceedings of Science
Volume	395
State	Published - 18 Mar 2022
Externally published	Yes
Event	37th International Cosmic Ray Conference, ICRC 2021 - Virtual, Berlin, Germany Duration: 12 Jul 2021 → 23 Jul 2021

Cite this

@article{d619a8278ecc47aa867b9279f7823328,

title = "UHECR mass composition from anisotropy of their arrival directions with the Telescope Array SD",

abstract = "We propose a new method for the estimation of ultra-high energy cosmic ray (UHECR) mass composition from a distribution of their arrival directions. The method employs a test statistic (TS) based on a characteristic deflection of UHECR events with respect to the distribution of luminous matter in the local Universe modeled with a flux-weighed 2MRS catalog. Making realistic simulations of the mock UHECR sets, we show that this TS is robust to the presence of galactic and non-extreme extra-galactic magnetic fields and sensitive to the mass composition of events in a set. We apply the method to Telescope Array surface detector data for 11 years and derive new independent constraints on fraction of protons and iron in p-Fe mix at E > 10 EeV. At 10 < E < 100 EeV the data favors increase of allowed proton fraction and decrease of allowed iron fraction, while at E > 100 EeV — pure iron or even more massive composition. This result is in tension with Auger composition model inferred from spectrum–Xmax fit at 2.7σ (2.0σ) for PT{\textquoteright}11 (JF{\textquoteright}12) regular GMF model.",

author = "\{the Telescope Array Collaboration\} and Mikhail Kuznetsov and Peter Tinyakov and Abbasi, \{R. U.\} and T. Abu-Zayyad and M. Allen and Y. Arai and R. Arimura and E. Barcikowski and Belz, \{J. W.\} and Bergman, \{D. R.\} and Blake, \{S. A.\} and I. Buckland and R. Cady and Cheon, \{B. G.\} and J. Chiba and M. Chikawa and T. Fujii and K. Fujisue and K. Fujita and R. Fujiwara and M. Fukushima and R. Fukushima and G. Furlich and R. Gonzalez and W. Hanlon and M. Hayashi and N. Hayashida and K. Hibino and R. Higuchi and K. Honda and D. Ikeda and T. Inadomi and N. Inoue and T. Ishii and H. Ito and D. Ivanov and H. Iwakura and A. Iwasaki and Jeong, \{H. M.\} and S. Jeong and Jui, \{C. C.H.\} and K. Kadota and F. Kakimoto and O. Kalashev and K. Kasahara and S. Kasami and H. Kawai and S. Kawakami and S. Kawana and Lee, \{K. H.\}",

note = "Publisher Copyright: {\textcopyright} Copyright owned by the author(s).; 37th International Cosmic Ray Conference, ICRC 2021 ; Conference date: 12-07-2021 Through 23-07-2021",

year = "2022",

month = mar,

day = "18",

language = "English",

volume = "395",

journal = "Proceedings of Science",

issn = "1824-8039",

publisher = "Sissa Medialab Srl",

}

TY - JOUR

T1 - UHECR mass composition from anisotropy of their arrival directions with the Telescope Array SD

AU - the Telescope Array Collaboration

AU - Kuznetsov, Mikhail

AU - Tinyakov, Peter

AU - Abbasi, R. U.

AU - Abu-Zayyad, T.

AU - Allen, M.

AU - Arai, Y.

AU - Arimura, R.

AU - Barcikowski, E.

AU - Belz, J. W.

AU - Bergman, D. R.

AU - Blake, S. A.

AU - Buckland, I.

AU - Cady, R.

AU - Cheon, B. G.

AU - Chiba, J.

AU - Chikawa, M.

AU - Fujii, T.

AU - Fujisue, K.

AU - Fujita, K.

AU - Fujiwara, R.

AU - Fukushima, M.

AU - Fukushima, R.

AU - Furlich, G.

AU - Gonzalez, R.

AU - Hanlon, W.

AU - Hayashi, M.

AU - Hayashida, N.

AU - Hibino, K.

AU - Higuchi, R.

AU - Honda, K.

AU - Ikeda, D.

AU - Inadomi, T.

AU - Inoue, N.

AU - Ishii, T.

AU - Ito, H.

AU - Ivanov, D.

AU - Iwakura, H.

AU - Iwasaki, A.

AU - Jeong, H. M.

AU - Jeong, S.

AU - Jui, C. C.H.

AU - Kadota, K.

AU - Kakimoto, F.

AU - Kalashev, O.

AU - Kasahara, K.

AU - Kasami, S.

AU - Kawai, H.

AU - Kawakami, S.

AU - Kawana, S.

AU - Lee, K. H.

PY - 2022/3/18

Y1 - 2022/3/18

N2 - We propose a new method for the estimation of ultra-high energy cosmic ray (UHECR) mass composition from a distribution of their arrival directions. The method employs a test statistic (TS) based on a characteristic deflection of UHECR events with respect to the distribution of luminous matter in the local Universe modeled with a flux-weighed 2MRS catalog. Making realistic simulations of the mock UHECR sets, we show that this TS is robust to the presence of galactic and non-extreme extra-galactic magnetic fields and sensitive to the mass composition of events in a set. We apply the method to Telescope Array surface detector data for 11 years and derive new independent constraints on fraction of protons and iron in p-Fe mix at E > 10 EeV. At 10 < E < 100 EeV the data favors increase of allowed proton fraction and decrease of allowed iron fraction, while at E > 100 EeV — pure iron or even more massive composition. This result is in tension with Auger composition model inferred from spectrum–Xmax fit at 2.7σ (2.0σ) for PT’11 (JF’12) regular GMF model.

AB - We propose a new method for the estimation of ultra-high energy cosmic ray (UHECR) mass composition from a distribution of their arrival directions. The method employs a test statistic (TS) based on a characteristic deflection of UHECR events with respect to the distribution of luminous matter in the local Universe modeled with a flux-weighed 2MRS catalog. Making realistic simulations of the mock UHECR sets, we show that this TS is robust to the presence of galactic and non-extreme extra-galactic magnetic fields and sensitive to the mass composition of events in a set. We apply the method to Telescope Array surface detector data for 11 years and derive new independent constraints on fraction of protons and iron in p-Fe mix at E > 10 EeV. At 10 < E < 100 EeV the data favors increase of allowed proton fraction and decrease of allowed iron fraction, while at E > 100 EeV — pure iron or even more massive composition. This result is in tension with Auger composition model inferred from spectrum–Xmax fit at 2.7σ (2.0σ) for PT’11 (JF’12) regular GMF model.

UR - https://www.scopus.com/pages/publications/85144129274

M3 - Conference article

AN - SCOPUS:85144129274

SN - 1824-8039

VL - 395

JO - Proceedings of Science

JF - Proceedings of Science

M1 - 294

T2 - 37th International Cosmic Ray Conference, ICRC 2021

Y2 - 12 July 2021 through 23 July 2021

ER -

UHECR mass composition from anisotropy of their arrival directions with the Telescope Array SD

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