Prof Subir Sarkar: Publications

IceCube

IceCube at 91̽��

I am a member since 2004 of the IceCube collaboration which discovered cosmic high energy neutrinos and identified some of their astrophysical sources.

IceCube @ 91̽��

Anisotropy in Pantheon+ supernovae

European Physical Journal C Springer 85:5 (2025) 596

Abstract:

We employ Maximum Likelihood Estimators to examine the Pantheon+ catalogue of Type Ia supernovae for large scale anisotropies in the expansion rate of the Universe. The analyses are carried out in the heliocentric frame, the CMB frame, as well as the Local Group frame. In all frames, the Hubble expansion rate in the redshift range 0.023 < z < 0.15 is found to have a statistically significant dipolar variation exceeding 1.5 km s−1 Mpc−1 , i.e. bigger than the claimed 1% uncertainty in the SH0ES measurement of the Hubble parameter H0. The deceleration parameter too has a redshift-dependent dipolar modulation at > 5σ significance, consistent with previous findings using the SDSSII/SNLS3 Joint Lightcurve Analysis catalogue. The inferred cosmic acceleration cannot therefore be due to a Cosmological Constant, but is likely a general relativistic effect due to the anomalous bulk flow in our local Universe.

Colloquium: The Cosmic Dipole Anomaly

(2025)

Authors:

Nathan Secrest, Sebastian von Hausegger, Mohamed Rameez, Roya Mohayaee, Subir Sarkar

Fast Low Energy Reconstruction using Convolutional Neural Networks

ArXiv 2505.16777 (2025)

Search for dark matter from the center of the Earth with 10 years of IceCube data

European Physical Journal C Springer Nature 85:5 (2025) 490

Authors:

R Abbasi, M Ackermann, J Adams, SK Agarwalla, JA Aguilar, M Ahlers, JM Alameddine, NM Amin, K Andeen, C Argüelles, Y Ashida, S Athanasiadou, SN Axani, R Babu, X Bai, A Balagopal V., M Baricevic, SW Barwick, S Bash, V Basu, R Bay, JJ Beatty, J Becker Tjus, J Beise, C Bellenghi, S BenZvi, D Berley, E Bernardini, DZ Besson, E Blaufuss, L Bloom, S Blot, F Bontempo, JY Book Motzkin, C Boscolo Meneguolo, S Böser, O Botner, J Böttcher, J Braun, B Brinson, Z Brisson-Tsavoussis, J Brostean-Kaiser, L Brusa, RT Burley, D Butterfield, MA Campana, I Caracas, K Carloni, J Carpio, S Chattopadhyay, N Chau, Z Chen, D Chirkin, S Choi, BA Clark, A Coleman, P Coleman, GH Collin, A Connolly, JM Conrad, R Corley, DF Cowen, C De Clercq, JJ DeLaunay, D Delgado, S Deng, A Desai, P Desiati, KD de Vries, G de Wasseige, T DeYoung, A Diaz, JC Díaz-Vélez, P Dierichs, M Dittmer, A Domi, L Draper, H Dujmovic, D Durnford, K Dutta, MA DuVernois, T Ehrhardt, L Eidenschink, A Eimer, P Eller, E Ellinger, S El Mentawi, D Elsässer, R Engel, H Erpenbeck, W Esmail, J Evans, PA Evenson, KL Fan, K Fang, K Farrag, AR Fazely, A Fedynitch, N Feigl, S Fiedlschuster, C Finley, L Fischer, D Fox, A Franckowiak, S Fukami, P Fürst, J Gallagher, E Ganster, A Garcia, M Garcia, G Garg, E Genton, L Gerhardt, A Ghadimi, C Girard-Carillo, C Glaser, T Glüsenkamp, JG Gonzalez, S Goswami, A Granados, D Grant, SJ Gray, S Griffin, S Griswold, KM Groth, D Guevel, C Günther, P Gutjahr, C Ha, C Haack, A Hallgren, L Halve, F Halzen, L Hamacher, H Hamdaoui, M Ha Minh, M Handt, K Hanson, J Hardin, AA Harnisch, P Hatch, A Haungs, J Häußler, K Helbing, J Hellrung, J Hermannsgabner, L Heuermann, N Heyer, S Hickford, A Hidvegi, C Hill, GC Hill, R Hmaid, KD Hoffman, S Hori, K Hoshina, M Hostert, W Hou, T Huber, K Hultqvist, M Hünnefeld, R Hussain, K Hymon, A Ishihara, W Iwakiri, M Jacquart, S Jain, O Janik, M Jansson, M Jeong, M Jin, BJP Jones, N Kamp, D Kang, W Kang, X Kang, A Kappes, D Kappesser, L Kardum, T Karg, M Karl, A Karle, A Katil, U Katz, M Kauer, JL Kelley, M Khanal, A Khatee Zathul, A Kheirandish, J Kiryluk, SR Klein, Y Kobayashi, A Kochocki, R Koirala, H Kolanoski, T Kontrimas, L Köpke, C Kopper, DJ Koskinen, P Koundal, M Kowalski, T Kozynets, N Krieger, J Krishnamoorthi, K Kruiswijk, E Krupczak, A Kumar, E Kun, N Kurahashi, N Lad, C Lagunas Gualda, M Lamoureux, MJ Larson, F Lauber, JP Lazar, JW Lee, K Leonard DeHolton, A Leszczyńska, J Liao, M Lincetto, YT Liu, M Liubarska, C Love, L Lu, F Lucarelli, W Luszczak, Y Lyu, J Madsen, E Magnus, KBM Mahn, Y Makino, E Manao, S Mancina, A Mand, W Marie Sainte, IC Mariş, S Marka, Z Marka, M Marsee, I Martinez-Soler, R Maruyama, F Mayhew, F McNally, JV Mead, K Meagher, S Mechbal, A Medina, M Meier, Y Merckx, L Merten, J Mitchell, T Montaruli, RW Moore, Y Morii, R Morse, M Moulai, T Mukherjee, R Naab, M Nakos, U Naumann, J Necker, A Negi, L Neste, M Neumann, H Niederhausen, MU Nisa, K Noda, A Noell, A Novikov, A Obertacke Pollmann, V O’Dell, A Olivas, R Orsoe, J Osborn, E O’Sullivan, V Palusova, H Pandya, N Park, GK Parker, V Parrish, EN Paudel, L Paul, C Pérez de los Heros, T Pernice, J Peterson, A Pizzuto, M Plum, A Pontén, Y Popovych, M Prado Rodriguez, B Pries, R Procter-Murphy, GT Przybylski, L Pyras, C Raab, J Rack-Helleis, N Rad, M Ravn, K Rawlins, Z Rechav, A Rehman, G Renzi, E Resconi, S Reusch, W Rhode, B Riedel, A Rifaie, EJ Roberts, S Robertson, S Rodan, G Roellinghoff, M Rongen, A Rosted, C Rott, T Ruhe, L Ruohan, D Ryckbosch, I Safa, J Saffer, D Salazar-Gallegos, P Sampathkumar, A Sandrock, M Santander, S Sarkar, S Sarkar, J Savelberg, P Savina, P Schaile, M Schaufel, H Schieler, S Schindler, L Schlickmann, B Schlüter, F Schlüter, N Schmeisser, T Schmidt, J Schneider, FG Schröder, L Schumacher, S Schwirn, S Sclafani, D Seckel, L Seen, M Seikh, M Seo, S Seunarine, P Sevle Myhr, R Shah, S Shefali, N Shimizu, M Silva, B Skrzypek, B Smithers, R Snihur, J Soedingrekso, A Søgaard, D Soldin, P Soldin, G Sommani, C Spannfellner, GM Spiczak, C Spiering, J Stachurska, M Stamatikos, T Stanev, T Stezelberger, T Stürwald, T Stuttard, GW Sullivan, I Taboada, S Ter-Antonyan, A Terliuk, M Thiesmeyer, WG Thompson, J Thwaites, S Tilav, K Tollefson, C Tönnis, S Toscano, D Tosi, A Trettin, R Turcotte, MA Unland Elorrieta, AK Upadhyay, K Upshaw, A Vaidyanathan, N Valtonen-Mattila, J Vandenbroucke, N van Eijndhoven, D Vannerom, J van Santen, J Vara, F Varsi, J Veitch-Michaelis, M Venugopal, M Vereecken, S Vergara Carrasco, S Verpoest, D Veske, A Vijai, C Walck, A Wang, C Weaver, P Weigel, A Weindl, J Weldert, AY Wen, C Wendt, J Werthebach, M Weyrauch, N Whitehorn, CH Wiebusch, DR Williams, L Witthaus, M Wolf, G Wrede, XW Xu, JP Yanez, E Yildizci, S Yoshida, R Young, S Yu, T Yuan, A Zegarelli, S Zhang, Z Zhang, P Zhelnin, P Zilberman, M Zimmerman

Galactic transient sources with the Cherenkov Telescope Array Observatory

Monthly Notices of the Royal Astronomical Society 91̽�� University Press 540:1 (2025) 205-238

Authors:

K Abe, S Abe, J Abhir, A Abhishek, F Acero, A Acharyya, R Adam, A Aguasca-Cabot, I Agudo, A Aguirre-Santaella, J Alfaro, R Alfaro, N Alvarez-Crespo, R Alves Batista, J-P Amans, E Amato, G Ambrosi, F Ambrosino, EO Angüner, LA Antonelli, C Aramo, C Arcaro, TTH Arnesen, K Asano

Abstract:

A wide variety of Galactic sources show transient emission at soft and hard X-ray energies: low- and high-mass X-ray binaries containing compact objects, isolated neutron stars exhibiting extreme variability as magnetars as well as pulsar-wind nebulae. Although most of them can show emission up to MeV and/or GeV energies, many have not yet been detected in the TeV domain by Imaging Atmospheric Cherenkov Telescopes. In this paper, we explore the feasibility of detecting new Galactic transients with the Cherenkov Telescope Array Observatory (CTAO) and the prospects for studying them with Target of Opportunity observations. We show that CTAO will likely detect new sources in the TeV regime, such as the massive microquasars in the Cygnus region, low-mass X-ray binaries with low-viewing angle, flaring emission from the Crab pulsar-wind nebula or other novae explosions, among others. Since some of these sources could also exhibit emission at larger time-scales, we additionally test their detectability at longer exposures. We finally discuss the multiwavelength synergies with other instruments and large astronomical facilities.

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