Newsletter French October/November 2022 Print E-mail

Logo ICRANet Logo ICRA Logo MAE

ICRANet Newsletter

Bulletin ICRANet
Octobre/Novembre 2022

1. 4 GCN ICRANet
2. Deuxième annonce du 5ème Zeldovich meeting, 12 - 17 Juin 2023, Erevan (Arménie)
3. Mission du Prof. Ruffini dans les Etats-Unis, 6-11 Novembre 2022: conférence au Cosmos Club, à l'Institute for Advanced Studies (IAS) et à l'Université de Princeton
4. Le Prof. Ruffini parmi le 2% des auteurs les plus cités, selon Elsevier
5. Félicitations au Prof. Narek Sahakyan, Directeur du centre ICRANet en Arménie et Professeur de la Faculté d'ICRANet, qui a reçu un Doctorat de Sciences (DSc) en physique, 22 Novembre 2022
6. Eclipse solaire partielle et mesure du diamètre solaire (25 Octobre 2022) et éclipse lunaire aux antipodes (8 Novembre 2022), événement online et podcast
7. Renouvellement du protocole de coopération entre l'ICRANet et l'Université Campus Bio-Medico de Rome (Italie), 11 Octobre 2022
8. Séminaires auprès du centre ICRANet, 25 Novembre 2022
9. Visites scientifiques auprès du centre ICRANet
10. Publications récentes

1. 4 GCN ICRANet

NUMBER: 32780
SUBJECT: GRB 221009A: A type I BdHN of exceptional energetics
DATE: 22/10/17 11:16:22 GMT
FROM: Remo Ruffini at ICRA

Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, M.Karlica, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, R. Ruffini, N.Sahakyan, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report:

GRB221009A detected by Swift (Kennea et al. 2022 GCN32635), Fermi-GBM(Veres et al. 2022, GCN32636, Lesage et al. 2022, GCN32642), Fermi-LAT(Bissaldi et al. 2022, GCN32637), with redshift of z=0.151 and an isotropic equivalent energy of Eiso=2x1054 erg (de Ugarte Postigo et al. 2022,GCN32648 and GCN32642) is a typical Binary driven Hypernova of type I (BdHNI), originating from the collapse of a carbon-oxygen core (CO-core) in presence of a companion neutron star (NS) with common feature with three BdHN I: GRB130427A with "pile up" in the prompt phase (Ruffini et al. 2013,GCN14526); GRB190114C (Ruffini et al. 2019, GCN23715); and GRB180720B(Ruffini et al. 2018, GCN23019). As the above three sources, GRB221009Apresents: 1) the optical (Lipunov et al. 2022, GCN32634 and GCN32639;Perley. 2022 GCN32638; Broens. 2022, GCN32640; Hu et al. 2022, GCN32644;Mondy: Belkin et al. 2022, GCN32645; de Wet et al.2022, GCN32646; Xu et al.2022 GCN32647; Odeh 2022, GCN32649; Brivio et al. 2022, GCN32652; Izzo et al. 2022, GCN32765), radio (Bright et al. 2022, GCN32653 and Farah et al.2022, GCN32655) and X-ray (Kennea et al, 2022, GCN32635, and GCN32651)synchrotron afterglow emissions as well as the TeV emission (Yong Huang et al. 2022, GCN32677), which in BdHN I originate from accreting millisecond spinning newborn NS (Rueda et al. 2022, e-Print: 2204.00579 [astro-ph.HE]);2) the ultra-relativistic prompt emission (UPE) phase (Moradi et al. 2021,PRD 104, 063043 and Rastegarnia et al. 2022, EPJC 82, 778) and GeV emission(Rueda et al 2022 ApJ 929 56) originated from the black hole formed by hypercritical accretion of the supernova ejecta on the NS companion; and 3) the optical emission of the nickel decay of the supernova (SN), created bythe collapse of the CO-core. The first evidence of the supernova rise is reported by S. Belkin et al. 2022, (GCN32769). In this GRB the bolometric optical peak of SN is expected to be observed at 15.57+/-2.0 days after the Fermi-GBM trigger (October 24th 2022, uncertainty from October 22nd 2022 to October 26th 2022, with the bolometric optical luminosity of L=(9.45+/-2.8) x1042 erg/s; Aimuratov et al. in preparation).


NUMBER: 32802
SUBJECT: GRB 221009A X-ray light-curve and the indication of TeV light-curve
DATE: 22/10/19 15:28:45 GMT
FROM: Remo Ruffini at ICRA

Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, M. Karlica, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, R. Ruffini, N. Sahakyan, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report:

LHAASO observed more than 5000 very high energy (VHE) photons in GRB 221009A, with the highest energy reaching 18 TeV (GCN 32677). Previously, high energy TeV emissions were also observed in GRB 180720B (Abdalla et al. 2019), 190114C (MAGIC Collaboration 2019), 190829A (H.E.S.S. Collaboration 2021) and 201216C (Blanch et al. GCN 29075). A common feature of these bursts is that the TeV light-curve follows a power-law decay with a similar index as the X-ray light-curve, and the TeV luminosity is tens of percent of the X-ray luminosity (see attached figure 1 and the references of Abdalla et al. 2019, MAGIC Collaboration 2019 and H.E.S.S. Collaboration 2021, Ruffini et al. 2021, Rueda et al. 2022, Rastegarnia et al. 2022, Wang et al. 2022). Here we present the X-ray light-curve of GRB 221009A observed by Swift-XRT (GCN 32651), and the t0 is taken from the Fermi-GBM trigger time (GCN 32636), see attached figure 2, a power-law of index -1.58 is fitted. The shadow region shows 20%-60% of the X-ray luminosity, which is expected to be the 0.3-1 TeV luminosity (17% less luminous for 0.5-18 TeV assuming a power-law spectrum of photon index -2) of this new burst if it shares the same behavior as the previous ones. We encourage further observations, especially the VHE observations, because this burst probably is more luminous than the previous ones, and it will be precious to have a late time (after days) VHE luminosity which was never achieved before, as well as the optical observations for the supernova appearance (GCN 32670, GCN 32780).

Figure 1: Figure 2:


NUMBER: 32808
SUBJECT: GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow
DATE: 22/10/20 14:57:47 GMT
FROM: Remo Ruffini at ICRA

Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, M. Karlica, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, R. Ruffini, N. Sahakyan, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report:

GRB 221009A appears to be a rare example (Jean-Luc Atteia et al. 2022, GCN 32793) of a particularly energetic and close GRB (de Ugarte Postigo et al. 2022, GCN 32648 and Lesage et al. 2022, GCN 32642 and N.P.M. Kuin et al. 2022, GCN 32656). Within the BdHN model, we have followed the X-ray, optical, and radio afterglows originating from synchrotron emission powered by fast spinning newborn neutron stars (vNS) with initial periods of fraction of a millisecond, accreting the supernova ejecta, created by the collapse of a carbon-oxygen core (Rueda et al. 2022, arXiv:2204.00579). Figures 1, 2 and 3 show the afterglows of three type I BdHNe, namely GRB 180720B (Ruffini et al. 2018, GCN 23019), GRB 190114C (Ruffini et al. 2019, GCN 23715), and GRB 211023A (Aimuratov et al. 2021, GCN 31056), and the prediction of their associated supernova. We have indicated the expected time of the occurrence of the supernova in GRB 221009A (Aimuratov et al. 2022, GCN 32780). The ongoing observations in optical, radio, and X-ray bands are strongly recommended for allowing the determination of the spin and magnetic field of the vNS. This will probe as well if the optical synchrotron emission, at ~ 106 s from the Fermi-GBM trigger, impedes the observations of the optical emission of the supernova originating from nickel decay (Aimuratov et al. in preparation, see also data from Ilfan Bikmaev et al. 2022, GCN 32752, and Jia. Ren et al. 2022, arXiv:2210.10673, reproduced in Fig. 4).

Fig1: Fig2:
Fig3: Fig4:


NUMBER: 32828
SUBJECT: GRB 221009A: Determination of the black holes mass and spin
DATE: 22/10/24 15:43:08 GMT
FROM: Remo Ruffini at ICRA

Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, M. Karlica, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, R. Ruffini, N. Sahakyan, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report:

In GRB 221009A, as in GRB 130427A (Ackermann et al. 2014, Science, 343, 42; and Ruffini et al. 2019, ApJ, 886, 82), the Fermi-GBM data in the prompt phase are piled up (Lesage et al. 2022, GCN 32642). In both cases there are missing the ultra-relativistic prompt emission (UPE) phases originating from quantum electro dynamical process around a Kerr BH (Ruffini et al. 2019, ApJ, 886, 82; and Rueda et al. 2022, ApJ, 929, 56), which were well observed in GRB 190114C (Moradi et al. 2021, Phys Rev D 104, 063043) and GRB 180720B (Rastegarnia et al. 2022, EPJC 82, 77). Under these conditions, for GRB 130427A the 0.1-100 GeV data of Fermi-LAT had allowed to determine only the lower limit on the BH mass, M>2.31 solar masses, and the upper limit of its spin parameter, α<0.4 (Ruffini et al. 2019, ApJ, 886, 82). For the BDHNI GRB 190114C (Ruffini et al. 2019, GCN 23715), the values of the BH mass and spin had been determined by taking into account the UPE contribution: M=4.53 solar masses, α=0.54 (Moradi et al. 2021, Phys Rev D 104, 063043). The analysis of GRB 130427A applied to GRB 221009A gives for the BH mass and spin parameters: M>2.36 solar masses and α<0.5. We identify the spike at 500s as the X-ray flare (see e.g. Ruffini et al. 2021 MNRAS 504, 5301-5326 for similar GRBs). We also identify the trigger in the 10 keV-10 MeV data of Fermi-GBM as the dawn of the supernova (SN-rise), associated with the gravitational collapse of the progenitor CO-core. The SN ejecta, accreting on the binary NS companion, give origin to the BH (BH rise, Rueda & Ruffini 2012, ApJ L, 758, L7) and accreting on the vNS they originate the afterglow (vNS rise, Ruffini et al. 2018, ApJ, 869.101; Becerra, et al. 2022, Phys Rev D 106, 083002). Additional data analysis from AGILE (GCN 32650), Fermi (GCN 32636, 32637, 32642, 32819), Swift (GCN 32635), LHAASO (GCN 32677), HXMT (Atel 15660) are needed to relate the SN-rise to the first appearance of the vNS (the vNS-rise) by the TeV radiation (GCN 32780, 32820, 32808), and also to relate the appearance of the BH (BH-rise) to the identification of the first GeV emission.

2. Deuxième annonce du 5ème Zeldovich meeting, 12 - 17 Juin 2023, Erevan (Arménie)

C'est avec plaisir que nous vous informons que la soumission des abstract pour le 5ème Zeldovich meeting est maintenant ouverte.

La liste des orateurs invités inclut:
• Gennady Bisnovatyi-Kogan, Institut de recherche spatiale (IKI), Russie
• Massimo Della Valle, Observatoire Astronomique de Capodimonte et INAF, Italie (TBC)
• Marat Gilfanov, Institut Max-Planck Institute d'Astrophysique, Allemagne et IKI, Russie (TBC)
• Paolo Giommi, Agence spatiale italienne (ASI), Italie
• Luca Izzo, Institut Niels Bohr, Danemark (TBC)
• Michael Kramer, Institut Max-Planck Institute de Radioastronomie, Allemagne (TBC)
• Jutta Kunz, Université de Oldenburg, Allemagne (TBC)
• Klaus Laemmerzahl, Université de Brême, Allemagne
• Di Li, Observatoire astronomique national de Chine, Chine
• Ruoyu Liu, Université de Nanjing, Chine
• Andrea Merloni, Institut Max-Planck Institute de Physique extraterrestre, Allemagne (TBC)
• Razmik Mirzoyan, Institut Max-Planck Institute de Physique, Allemagne
• Tsvi Piran, Université hébraïque de Jérusalem, Israël
• Konstantin Postnov, Institut d'Astronomie Sternberg, Université d'État de Moscou, Russie
• Rashid Sunyaev, Institut Max-Planck Institute d'Astrophysique, Allemagne et IKI, Russie (TBC)
• Alexei Starobinsky, Institute Landau pour la physique théorique, Russie
• Lev Titarchuk, Université de Ferrara, Italie et Astro Space Center, Institut de Physique Lebedev, Russie
• Nan Zhang, Institute de Physique des hautes énergies, Chine

Lors du 5ème Zeldovich meeting, les nouvelles découvertes par les principales missions scientifiques en astrophysique relativiste seront illustrées:
• le télescope russe - allemand Spektr-RG (SRG)
• le télescope américain - européen - canadien James Webb Space Telescope (JWST)
• l'italo-américain Imaging X-ray Polarimetry Explorer (IXPE)
• la mission chinoise - européenne enhanced X-ray Timing and Polarimetry mission (eXTP)
• l'observatoire chinois Large High Altitude Air Shower Observatory (LHAASO)
• le télescope chinois Five-hundred-meter Aperture Spherical Telescope (FAST)
• le télescope européen Major Atmospheric Gamma Imaging Cherenkov Telescope (MAGIC)

Les frais d'inscription anticipée sont de 300 euro (100 euro pour les étudiants). Les frais d'inscription Tardifs seront de 400 euro (150 euro pour les étudiants). Ces frais incluent le kit de la conférence, les pauses café et la publication des actes de la conférence.
Pour le poster du meeting:
Pour le site web du meeting:

3. Mission du Prof. Ruffini dans les Etats-Unis, 6-11 Novembre 2022: conférence au Cosmos Club, à l'Institute for Advanced Studies (IAS) et à l'Université de Princeton

Du 6 à l'11 Novembre 2022, le Prof. Remo Ruffini, Directeur d'ICRANet, a visité les Etats Unis. Pendant sa visite, il a été invité à présenter un séminaire auprès du prestigieux Cosmos Club a Washington DC, dans la journée de lundi 7 Novembre, a 11:30 h EST, titré "The Role of Supernovae in Triggering the Formation of a Black Hole in Gamma Ray Bursts"; voici ci-dessous le résumé:
Supernovae of constant luminosities, with a tight neutron star companion, trigger complex systems leading to the formation of fast rotating Kerr Black Holes. Their rotational energy feeds gamma ray bursts which are extremely luminous. This presentation identifies extensions of known physical laws, inquiring on the unique role of these cosmic events. We follow their implications for the life evolution of our universe.
We also present recent understanding on the largest ever GRB221009A exploded on last October 19 and followed by the largest number of Observatories in all wavelengths from the ground and from space, from radio all the way to MeV, GeV and TeV radiation and UHCR.

Fig. 1: annonce du séminaire du Prof. Remo Ruffini auprès du cosmos Club, Washington DC, 7 Novembre 2022. Fig. 2: le Prof. Remo Ruffini devant le mur du Cosmos Club à Washington avec tous les membres qui ont reçu les Prix Nobel.

Le jour suivant, 8 Novembre, le Prof. Ruffini s'est déplacé à Princeton, puisque il a été invité à participer au typique Bahcall lunch auprès de l'Institute for Advanced Studies (IAS), un déjeuner spécial et collectif, à la fois pour les astrophysiques et les physique, les membre de l'Institut et de la Faculté dans la Dilworth Room, Simons Hall.
Suite au déjeuner, le Prof. Ruffini s'est déplacé à l'Université de Princeton, où il avait été invite à presenter son séminaire titré "The Role of Supernovae in Triggering the Formation of a Black Hole in Gamma Ray Bursts" dans la Jadwin Hall, dans la nouvelle section Gravity Initiative.
Alors qu'à l'Université de Princeton, le Prof. Ruffini a rencontré, parmi les autres, le Prof. Neta Bahcall, le Prof. Lyman Page et le Prof. Bruce Partridge et a profité de cette occasion pour avoir avec eux des fructueux débats scientifiques.
Dans les jours suivants, le Prof. Ruffini a rencontré aussi le Dr David Nirenberg, Directeur du IAS, pour discuter avec lui des questions scientifiques importantes tandis que des résultats récents obtenu par le group ICRANet. Il a aussi visité la bibliothèque de l'Université de Princeton et rencontré la Dr Abigail Johnson, de la Princeton University Press, avec laquelle il a discuté de questions éditoriales importantes.

Fig. 3: de gauche à droite: le Prof. Remo Ruffini, la Prof. Neta Bahcall, le Prof. Lyman Page et le Prof. Bruce Partridge. Fig. 4: le Prof. Ruffini avec la Dr Abigail Johnson (Princeton University Press).

4. Le Prof. Ruffini parmi le 2% des auteurs les plus cités, selon Elsevier

La récente mise à jour de la base de données d'accès public des plus de 100.000 scientifiques énumérés par Elsevier, a montré que le Prof. Remo Ruffini (Directeur d'ICRANet), le Prof. Behzad Eslam Panah (ICRANet-Mazandaran, Iran) et plusieurs autres scientifiques d'ICRANet sont dans cette liste.
Elsevier a créé cette base de données d'accès public des scientifiques les plus cités, qui donne des informations normalisées sur les citations, le h-index, la co-authorship, le hm-index ajusté et la citation des articles dans différents positions de paternité. Les scientifiques sont classifiés dans 22 domaines scientifiques et 174 sous-champs, qui sont fournis pour tous les scientifiques avec au moins 5 articles. Les données au long de la carrière sont mis à jour jusqu'à la fin du 2021 et les données singles de l'année récente se rapportent aux citations reçues pendant le 2021. La sélection se base sur les meilleures 100.000 scientifiques par c-score (avec et sans auto citations) ou un rang centile du 2% ou au-dessus dans le sous-champ. Cette version de la liste repose sur la photo au 1 Septembre 2021 par Scopus, mise à jour jusqu'à la fin de l'année de référence 2021. Ce travail utilise les donnés de Scopus, fournies par Elsevier à travers le ICSR Lab ( et les calcules sont réalisés en utilisant tous les profil des auteurs sur Scopus dès le 1 Septembre 2022.

5. Félicitations au Prof. Narek Sahakyan, Directeur du centre ICRANet en Arménie et Professeur de la Faculté d'ICRANet, qui a reçu un Doctorat de Sciences (DSc) en physique, 22 Novembre 2022

C'est avec plaisir que nous vous informons que le 22 Novembre 2022, le Prof. Narek Sahakyan, Directeur du centre ICRANet en Arménie, a reçu un Doctorat de Sciences (DSc) en physique, comme annoncé par la Higher Attestation Commission (VAK) d'Arménie ( Sa these "Study of multiwavelength and neutrino emission from blazars" a été défendue avec succès le 25 Juin 2022.
Le Prof. Sahakyan est donc devenu un des rares jeunes chercheurs arméniens, âgé de moins de 40 ans, qui ont obtenu ce haut degré scientifique dans le pays.

6. Eclipse solaire partielle et mesure du diamètre solaire (25 Octobre 2022) et éclipse lunaire aux antipodes (8 Novembre 2022), événement online et podcast

Eclipse solaire partielle et mesure du diamètre solaire (25 Octobre 2022)
A l'occasion de l'éclipse solaire partielle du 25 Octobre 2022, le Prof. Costantino Sigismondi, collaborateur d'ICRANet, a organisé un meeting en ligne et podcast, dans le cadre d'un projet mené avec des étudiants des lycées de Pescara, Rome et Motta di Liveza (Italie), sur la mesure du diamètre solaire.
Cet étude fait partie d'un projet d'astrométrie, structuré comme suit: Eclipses, équinoxes et couchers du soleil: les méthodes pour apprivoiser les chevaux du Soleil. Le wagon mythologique de Febo est canalisé dans une orbite précise, dont les paramètres font l'objet d'étude de la Mécanique céleste. les astronomes après Galileo, avec cette phrase, font allusion à la compréhension du phénomène de la réfraction atmosphérique qui a été mesuré exactement avec le Soleil entre 20° et 70° du Zénith par Giandomenico Cassini en 1655, après avoir été mesuré par Tycho Brahe en 1572 avec la Supernova en Cassiopée observée par toute l'Europe.
Le Prof. Sigismondi a illustré les suivants méthodes observationnels ainsi que d'analyse des données avec les mesures de la position et du diamètre du soleil méridiennes et sur l'horizon : éléments d'astrométrie (systèmes de coordonnées célestes, ascension droite et déclination, longitude écliptique et latitude) ; les saisons d'un point de vue astronomique (la forme de l'orbite de la Terre : excentricité et ligne des apsides), la forme et la dimension de la Terre à partir des données de la méridienne à Rome S. Maria degli Angeli et dei Martiri à Motta di Livenza, le timing d'une observation astronomique en utilisant la vidéo synchronisée avec UTC, le timing d'une observation astronomique d'une webcam et la synchronisation avec le protocole NTP, les éphémérides astronomiques NASA, IMCCE et le program Stellarium, l'ajustement linéaire sur les données par l'équinoxe automnal en 2022, l'ajustement quadratique sur les données par le solstice en 2022, l'ajustement quadratique sur les données par l'éclipse solaire partielle le 25 Octobre 2022 et la base de données en ligne des observations tenues au méridien Clémentin ainsi que la feuille de travail pour la réduction de ces données.
Pour le fondement scientifique de cet événement:
Pour les vidéos analyses pendant cet événement:
Pour la playlist YouTube sur l'éclipse solaire du 25 Octobre 2022:

L'éclipse lunaire aux antipodes (8 Novembre 2022)
Fig. 5: simulation du transit méridien lunaire le 7 Novembre 2022 Fig. 6: simulation du transit méridien lunaire le 9 Novembre 2022

L'éclipse lunaire aux antipodes a été observée grâce aux calculs (8 Novembre 2022).
En effet, dans chaque saison des éclipses, chaque 6 mois draconitiques, les éclipses se manifestent par deux, parfois aussi par trois. Toutes ces statistiques sont des héritages de la mécanique céleste et le Prof. Costantino Sigismondi, collaborateur d'ICRANet, a revenu sur les étapes principales à travers 2 événements.
Le premier a eu lieu le 5 Novembre 2022 auprès de la Basilique de S. Maria degli Angeli (Rome). Sur la ligne clémentine ont été simulés les passages méridiens de la Lune le 7 et le 9 Novembre 2022 ainsi qu'a été calculé l'interpolation le 8 Novembre, imposant la condition de l'alignement entre les centres de la Lune, de la Terre et du Soleil. Il a été enfin découvert que la Lune serait presque à 180° du Soleil le 8 Novembre 2022 à 12:00 h.
Le deuxième a eu lieu le 8 Novembre, à travers le lien au site web Timeanddate, ou les images de l'éclipse ont été transmises: Dans le même temps, le Prof. Sigismondi a fourni un commentaire en Italien sur les aspects scientifiques et historiques.
Les éclipses lunaires ont été utilisées pour mesurer la longitude du point d'observation, en disposant d'un méridien. Elles représentent la méthode la plus précise pour ce but jusqu'à la fin de la totalité du XVIII siècle. Cristoforo Colombo aussi avait évalué la longitude de Hispaniola avec l'éclipse de Lune du 29 Février 1504. Le Prof. Sigismondi a ensuite illustré toutes les éclipses lunaires qu'il a observe, à partir de celle du 9 Janvier 1982 à Lanciano, répétée après un cycle de Saros le 21 Janvier 2000, tandis qu'il était in Padoue, ainsi qu'après un cycle de Metone le 21 Janvier 2019 à Pescara et le 7 Aout 2017 du Pont Sant'Angelo bridge à Rome. La dernière éclipse qu'il a observé a été le 16 Mai 2022 à Lanciano.
Pour le site web du meeting, ainsi que pour les références aux travaux qui concernent les éclipses de Lune:

7. Renouvellement du protocole de coopération entre l'ICRANet et l'Université Campus Bio-Medico de Rome (Italie), 11 Octobre 2022

Le 11 Octobre 2022, le Protocole de Coopération entre l'ICRANet et l'Université Campus Bio-medico de Rome a été renouvelé. Cet accord demeurera valide pour 2 années et les principales activités conjointes qui seront développées dans le cadre de cet accord comptent: la promotion des activités de recherche et d'observation dans le champ de l'astrophysique relativiste; la collaboration entre des membres de la Faculté, des chercheurs, des post-doctorat fellows et des étudiants; l'organisation de séminaires, conférences, workshops, cours de formations et de recherche, et publications conjointes.
Pour le texte du protocole:

8. Séminaires auprès du centre ICRANet, 25 Novembre 2022

Séminaire du Prof. Gennady Bisnovatyi-Kogan
Le vendredi 25 Novembre 2022, le Prof. Gennady Bisnovatyi-Kogan (Institut de recherche spatiale de l'Académie des Sciences de Russie) a présenté un séminaire titré "About the Observational Check of the Mechanism of Gamma Radiation in Soft Gamma Repeaters (SGR)"; voici ci-dessous le résumé:
Soft gamma repeaters (SGR) are identified as single neutron stars (NS) inside the Galaxy, or nearby galaxies, with sporadic transient gamma radiation. A total number of discovered SGR, including relative Anomalous X-ray pulsars (AXP), is a few tens of objects. Many of them show periodic radiation, connected with NS rotation, with periods 2-12 s. The slow rotation is accompanied by small rate of loss of rotational energy, which is considerably smaller than the observed sporadic gamma ray luminosity, and is many orders less than the luminosity during giant bursts, observed in 4 SGR. Therefore the energy source is usually connected with annihilation of a very strong NS magnetic field. Another model is based on the release of nuclear energy stored in the NS non-equilibrium layer. We suggest here an observational test which could distinguish between these two models.
L'annonce du séminaire a été aussi publié sur le site web d'ICRANet:
Pour la vidéo du séminaire:

Fig. 7 et 8: le Prof. Gennady Bisnovatyi-Kogan en présentant son séminaire auprès du centre ICRANet à Pescara, 25 Novembre 2022.

Séminaire du Prof. Marco Merafina
Le vendredi 25 Novembre 2022, le Prof. Marco Merafina (Université de Rome La Sapienza) a présenté un séminaire titré "Multimass King models with Kroupa mass function"; voici ci-dessous le résumé:
Statistical analysis on Milky Way globular clusters distribution is developed in order to extract the best fit function and carry out the critical value of the onset of gravothermal catastrophe, connected with the maximum of the distribution function. Results show that gravothermal collapse for globular clusters onsets earlier than commonly believed and in accordance with theoretical results obtained by considering the presence of the effective potential which describes the effects of the tidal forces induced by the hosting galaxy. N-body simulations confirm the presence of the effective potential with the predicted form. Theoretical model is generalized to multimass one by using Kroupa mass function. A detailed description of the projected densities at different W0 indicates similar luminosity profiles in complete accordance with observations. We also consider the effects of the mass segregation on the distribution of stars and the consequences on the equipartition process. N-body simulations in connection with mass distribution and segregation as well the computational development applied to multimass model are also shown at the present state of the art.
L'annonce du séminaire a été aussi publié sur le site web d'ICRANet:
Pour la vidéo du séminaire:

Fig. 9 and 10: Prof. Marco Merafina giving his seminar at ICRANet center in Pescara, November 25, 2022.

9. Visites scientifiques auprès du centre ICRANet

• Prof. Seyed Mohammad Taghi Mirtorabi (Alzahra University - Iran), 1 - 18 Octobre 2022
• Prof. Massimo Della Valle (Observatoire de Capodimonte - Italie), 30 Octobre - 1 Novembre 2022
• Prof. Gennady Bisnovatyi-Kogan (Institut de recherche spatiale de l'Académie des Sciences de Russie - SRI RAS), 25 - 27 Novembre 2022
• Prof. Marco Merafina (Université de Rome La Sapienza), 25 Novembre 2022

Prof. Seyed Mohammad Taghi Mirtorabi Prof. Massimo Della Valle Prof. Gennady Bisnovatyi-Kogan Prof. Marco Merafina

Pendant leur visite, ils ont eu l'opportunité de discuter de leur travaux de recherché et d'avoir des intéressants échanges d'opinion avec les autres chercheurs ICRANet de toutes les parties du monde.

10. Publications récentes

J. A. Rueda, Liang Li, R. Moradi, R. Ruffini, N. Sahakyan, and Y. Wang, On the X-Ray, Optical, and Radio Afterglows of the BdHN I GRB 180720B Generated by Synchrotron Emission, published on November 3, 2022 in ApJ, Volume 939, Number 2.
Gamma-ray bursts (GRBs) are systems of unprecedented complexity across all the electromagnetic spectrum, including the radio, optical, X-rays, gamma rays in the MeV and GeV regimes, as well as ultrahigh-energy cosmic rays, each manifested in seven specific physical processes with widely different characteristic evolution timescales ranging from 10−14 s to 107 s or longer. We here study the long GRB 180720B originating from a binary system composed of a massive carbon-oxygen (CO) star of about 10M⊙ and a companion neutron star (NS). The gravitational collapse of the CO star gives rise to a spinning newborn NS (νNS), with an initial period of P0 = 1 ms that powers the synchrotron radiation in the radio, optical, and X-ray wavelengths. We here investigate solely the GRB 180720B afterglows and present a detailed treatment of its origin based on the synchrotron radiation released by the interaction of the νNS and the SN ejecta. We show that in parallel to the X-ray afterglow, the spinning νNS also powers the optical and radio afterglows and allows to infer the νNS and ejecta parameters that fit the observational data.

J. A. Rueda, R. Ruffini, L. Li, R. Moradi, J. F. Rodriguez, and Y. Wang, Evidence for the transition of a Jacobi ellipsoid into a Maclaurin spheroid in gamma-ray bursts, published on October 7, 2022 in Phys. Rev. D 106, 083004.
In the binary-driven hypernova (BdHN) scenario, long gamma-ray bursts (GRBs) originate in a cataclysmic event that occurs in a binary system composed of a carbon-oxygen (CO) star and a neutron star (NS) companion in close orbit. The collapse of the CO star generates at its center a newborn NS (νNS), and a supernova (SN) explosion. Matter from the ejecta is accreted both onto the νNS because of fallback and onto the NS companion, leading to the collapse of the latter into a black hole (BH). Each of the ingredients of the above system leads to observable emission episodes in a GRB. In particular, the νNS is expected to show up (hereafter νNS−rise) in the early GRB emission, nearly contemporary or superimposed to the ultrarelativistic prompt emission (UPE) phase, but with a different spectral signature. Following the νNS−rise, the νNS powers the afterglow emission by injecting energy into the expanding ejecta leading to synchrotron radiation. We here show that the νNS−rise and the subsequent afterglow emission in both systems, GRB 180720B and GRB 190114C, are powered by the release of rotational energy of a Maclaurin spheroid, starting from the bifurcation point to the Jacobi ellipsoid sequence. This implies that the νNS evolves from a triaxial Jacobi configuration, prior to the νNS−rise, into the axially symmetric Maclaurin configuration observed in the GRB. The triaxial νNS configuration is short-lived (less than a second) due to a copious emission of gravitational waves, before the GRB emission, and it could be in principle detected for sources located at distances closer than 100 Mpc. This appears to be a specific process of emission of gravitational waves in the BdHN I powering long GRBs.

L. M. Becerra, R. Moradi, J. A. Rueda, R. Ruffini, and Y. Wang, First minutes of a binary-driven hypernova, published on October 3, 2022 in Phys. Rev. D 106, 083002.
We simulate the first minutes of the evolution of a binary-driven hypernova event, with a special focus on the associated accretion processes of supernova ejecta onto the newborn neutron star (νNS) and the NS companion. We calculate the rotational evolution of the νNS and the NS under the torques exerted by the accreted matter and the magnetic field. We take into account general relativistic effects through effective models for the NSs binding energy and the specific angular momentum transferred by the accreted matter. We use realistic hypercritical accretion rates obtained from three-dimensional smoothed-particle-hydrodynamics numerical simulations of the binary-driven hypernova event for a variety of orbital periods. We show that the rotation power of the νNS has a unique double-peak structure while that of the NS has a single peak. These peaks are of comparable intensity and can occur very close in time or even simultaneously depending on the orbital period and the initial angular momentum of the stars. We outline the consequences of the above features in the early emission and their consequent observation in long gamma-ray bursts.

Carvalho, G. A.; Anjos, R. C. dos; Coelho, J. G.; Lobato, R. V.; Malheiro, M.; Marinho, R. M.; Rodriguez, J. F.; Rueda, J. A.; Ruffini, R., Orbital Decay of Double White Dwarfs: Beyond Gravitational-wave Radiation Effects, published on November 23, 2022 in ApJ, Vol. 940, n. 1.
The traditional description of the orbital evolution of compact-object binaries, like double white dwarfs (DWDs), assumes that the system is driven only by gravitational-wave (GW) radiation. However, the high magnetic fields with intensities of up to gigagausses measured in WDs alert a potential role of the electromagnetic (EM) emission in the evolution of DWDs. We evaluate the orbital dynamics of DWDs under the effects of GW radiation, tidal synchronization, and EM emission by a unipolar inductor generated by the magnetic primary and the relative motion of the nonmagnetic secondary. We show that the EM emission can affect the orbital dynamics for magnetic fields larger than megagausses. We applied the model to two known DWDs, SDSS J0651+2844 and ZTF J1539+5027, for which the GW radiation alone does not fully account for the measured orbital decay rate. We obtain upper limits to the primary's magnetic field strength, over which the EM emission causes an orbital decay faster than observed. The contribution of tidal locking and the EM emission is comparable, and together they can contribute up to 20% to the measured orbital decay rate. We show that the gravitational waveform for a DWD modeled as purely driven by GWs and including tidal interactions and EM emission can have large relative dephasing detectable in the mHz regime of frequencies relevant for space-based detectors like LISA. Therefore, including physics besides GW radiation in the waveform templates is essential to calibrate the GW detectors using known sources, e.g., ZTF J1539+5027, and to infer binary parameters.
DOI: 10.3847/1538-4357/ac9841

S-S. Xue, W boson mass tension caused by its right-handed gauge coupling at high energies?, published on October 16, 2022 in Nuclear Physics B, Volume 985.
The CDF collaboration's recent high-precision measurement of the W mass is in 7.0σ disagreement with the Standard Model expectation. This tension will be relieved if the W boson has a non-trivial right-handed gauge coupling at high energies. At TeV scales, the SM gauge symmetric four-fermion interactions induce a right-handed gauge coupling, and SM fermions compose massive composite particles. We investigate the top-quark mass produced by spontaneous symmetry breaking and compute the W and Z boson propagators and decays. The right-handed coupling corrections to their masses and widths are consistent with experimental measurements. We discuss how SM gauge bosons and composite particles can restore parity-preserving gauge symmetries at TeV scales.

N. Sahakyan, D. Israyelyan, G. Harutyunyan, S. Gasparyan, V. Vardanyan, M. Khachatryan, Modelling the time variable spectral energy distribution of the blazar CTA 102 from 2008 to 2022, published on October 2, 2022 in Monthly Notices of the Royal Astronomical Society.
We present long-term multiwavelength observations of blazar CTA 102 (z = 1.037). Detailed temporal and spectral analyses of γ-ray, X-ray, and UV/optical data observed by Fermi-LAT, Swift XRT, NuSTAR, and Swift-UVOT over a period of 14 yr, between 2008 August and 2022 March, were performed. We found strong variability of source emission in all the considered bands; especially in the γ-ray band it exhibited extreme outbursts when the flux crossed the level of 10−5 photon cm−2 s−1. Using the Bayesian Blocks algorithm, we split the adaptively binned γ-ray light curve into 347 intervals of quiescent and flaring episodes and for each period built corresponding multiwavelength spectral energy distributions (SEDs), using the available data. Among the considered SEDs, 117 high-quality (quasi) contemporaneous SEDs, which have sufficient multiwavelength data, were modelled using JETSET framework within a one-zone leptonic synchrotron and inverse-Compton emission scenario assuming the emitting region is within the broad-line region and considering internal and external seed photons for the inverse-Compton up scattering. As a result of modelling, the characteristics of the relativistic electron distribution in the jet as well as jet properties are retrieved and their variation in time is investigated. The applied model can adequately explain the assembled SEDs and the modelling shows that the data in the bright flaring periods can be reproduced for high Doppler boosting and magnetic field. The obtained results are discussed in the context of particle cooling in the emitting region.

B. Eslam Panah, Two-dimensional Lifshitz-like AdS black holes in F(R) gravity, published on November 2 in the Journal of Mathematical Physics 63, 112502 (2022).
Two-dimensional (2D) Lifshitz-like black holes in special F(R) gravity cases are extracted. We indicate an essential singularity at r = 0, covered by an event horizon. Then, conserved and thermodynamic quantities, such as temperature, mass, entropy, and the heat capacity of 2D Lifshitz-like black holes in F(R) gravity, are evaluated. Our analysis shows that 2D Lifshitz-like black hole solutions can be physical solutions, provided that the cosmological constant is negative (Λ < 0). Indeed, there is a phase transition between stable and unstable cases by increasing the radius of AdS black holes. In other words, the 2D Lifshitz-like AdS black holes with large radii are physical and enjoy thermal stability. The obtained 2D Lifshitz-like AdS-black holes in F(R) gravity turn into the well-known 2D Schwarzschild AdS-black holes when the Lifshitz-like parameter is zero (s = 0). Moreover, correspondence between these black hole solutions and the 2D rotating black hole solutions is found by adjusting the Lifshitz-like parameter.

A. Bagheri Tudeshki, G. H. Bordbar, and B. Eslam Panah, Dark Energy Star in Gravity's Rainbow, published on October 19 in Physics Letters B. 835, 137523 (2022).
The concept of dark energy can be a candidate for preventing the gravitational collapse of compact objects to singularities. According to the usefulness of gravity's rainbow in UV completion of general relativity (by providing a new description of spacetime), it can be an excellent option to study the behavior of compact objects near phase transition regions. In this work, we obtain a modified Tolman-Openheimer-Volkof (TOV) equation for anisotropic dark energy as a fluid by solving the field equations in gravity's rainbow. Next, to compare the results with general relativity, we use a generalized Tolman-Matese-Whitman mass function to determine the physical quantities such as energy density, radial pressure, transverse pressure, gravity profile, and anisotropy factor of the dark energy star. We evaluate the junction condition and investigate the dynamical stability of dark energy star thin shell in gravity's rainbow. We also study the energy conditions for the interior region of this star. We show that the coefficients of gravity's rainbow can significantly affect this non-singular compact object and modify the model near the phase transition region.

García, Cristhian; Santa, Camilo; Romano, Antonio Enea, Deep learning reconstruction of the large scale structure of the Universe from luminosity distance, published on October 19, 2022 in Monthly Notices of the Royal Astronomical Society.
Supernovae Ia (SNe) can provide a unique window on the large-scale structure (LSS) of the Universe at redshifts where few other observations are available, by solving the inversion problem (IP) consisting in reconstructing the LSS from its effects on the observed luminosity distance. So far the IP was solved assuming some restrictions about space-time, such as spherical symmetry for example, while we obtain for the first time solutions of the IP problem for arbitrary space-time geometries using deep learning. The method is based on the use of convolutional neural networks (CNN) trained on simulated data. The training data set is obtained by first generating random density and velocity fields, and then computing their effects on the luminosity distance. The CNN, based on an appropriately modified version of U-Net to account for the tridimensionality of the data, is then trained to reconstruct the density and velocity fields from the luminosity distance. We find that the velocity field inversion is more accurate than the density field, because the effects of the velocity on the luminosity distance only depend on the source velocity, while in the case of the density it is an integrated effect along the line of sight, giving rise to more degeneracy in the solution of the IP. Improved versions of these neural networks, modified to accommodate the non-uniform distribution of the SNe, can be applied to observational data to reconstruct the LSS of the Universe at redshifts at which few other observations are available.

Cadavid, Alexander Gallego; Romano, Antonio Enea; Liddle, Andrew R., Reconstructing homospectral inflationary potentials, published on October 13, 2022 in Phys. Rev. D 106, 083512.
Purely geometrical arguments show that there exist classes of homospectral inflationary cosmologies, i.e., different expansion histories producing the same spectrum of comoving curvature perturbations. We develop a general algorithm to reconstruct the potential of minimally coupled single scalar fields from an arbitrary expansion history. We apply it to homospectral expansion histories to obtain the corresponding potentials, providing numerical and analytical examples. The infinite class of homospectral potentials depends on two free parameters, the initial energy scale and the initial value of the field, showing that, in general, it is impossible to reconstruct a unique potential from the curvature spectrum unless the initial energy scale and the field value are fixed, for instance, through observation of primordial gravitational waves.
ICRANet Seats
Director and Staff
Personal Pages
Official Documents
Scientific Agreements
Annual reports
Upcoming Meetings
Marcel Grossmann
Galileo - Xu Guangqi
C. Lattes Meeting
Bego Scientific Rencontre
Zeldovich Meetings
Meetings in Armenia
Past meeting series
Single meetings
ICRANet Workshops
Other Meetings
IRAP Ph.D. Schools
Weekly Seminars
Research Groups
Press releases
Recorded talks
Public Events
Visitors: 166203904