Conveners
Galactic and extragalactic magnetars: recent observations and theoretical progress: Thursday block 1
- Sandro Mereghetti ()
- Simone Dall'Osso (Sapienza Universita' di Roma)
Galactic and extragalactic magnetars: recent observations and theoretical progress: Thursday block 2
- Sandro Mereghetti ()
- Simone Dall'Osso (Sapienza Universita' di Roma)
Galactic and extragalactic magnetars: recent observations and theoretical progress: Friday block 1
- Sandro Mereghetti ()
- Simone Dall'Osso (Sapienza Universita' di Roma)
Galactic and extragalactic magnetars: recent observations and theoretical progress: Friday block 2
- Sandro Mereghetti ()
- Simone Dall'Osso (Sapienza Universita' di Roma)
Description
Magnetars, neutron stars powered mainly by their own magnetic energy, host the strongest magnetic fields in the Universe. Besides being unique laboratories to test physical theories in the strong field regime, their energetic outbursts on different timescales and the extreme properties of their birth events makes them relevant in diverse astrophysical contexts. Recent progress in this field has also been driven by the recognition of an expanding number of giant flares from magnetars outside the Local Group.
This parallel session will focus on the most recent observational results on Galactic and extraGalactic magnetars, as well as on the theoretical developments on their structure, formation and connections with other astrophysical phenomena (such as, e.g., fast radio bursts, gamma-ray bursts, super luminous supernovae, sources of high-energy cosmic rays, neutrinos and gravitational waves).
Magnetars are the strongest magnets we know of, with magnetic fields reaching values up to 10^15 G at the surface. Transient activity in the X-/gamma ray regime is the birthmark of magnetars. Their radiative variability includes short, explosive events from milliseconds to hundreds of seconds (i.e., bursts and giant flares) and longer-lived outbursts (weeks to months). In this talk, I will...
Magnetars are isolated young neutron stars that exhibit the most intense magnetic fields known in the Universe and are characterized by a wide variety of high-energy emissions. The birth of rapidly rotating magnetars is also a promising scenario to power outstanding explosive transients. The formation process of these objects, as well as the origin of their ultra-strong magnetic fields,...
Most of our knowledge about magnetars and pulsars is based on high-energy or radio observations. Due to the faintness of neutron stars in the infrared and the limited availability of space missions covering the wavelengths between millimeter wavelengths and the visible light, infrared studies of these compact objects are sparse. Yet, there is a lot of discovery potential at these wavelengths....
We have investigated the evolutionary links between the isolated neutron star populations namely radio pulsars (RPs), anomalous X-ray pulsars (AXPs), soft gamma repeaters (SGRs), dim isolated neutron stars (XDINs), high-magnetic-field RPs (HBRPs), central compact objects (CCOs), rotating radio transients (RRATs), and long-period pulsars (LPPs) in the fallback disc model. The results of our...
Magnetars were discovered as soft gamma-ray repeaters by gamma-ray burst monitors. Their most energetic events are giant flares, seen as a bright, short flash followed by an exponentially-decaying periodic tail. There have been 3 such events seen in the Milky Way and Large Magellanic Cloud in ~60 years of observing. When these events occur in nearby galaxies their tail emission is...
3XMM J185246.6+003317 is a transient magnetar located in the vicinity of the supernova remnant Kes\,79. So far, observations have only set upper limits to its surface magnetic field and spindown, and there is no estimate for its mass and radius. Using ray-tracing modelling and Bayesian inference for the analysis of several light curves spanning a period of around three weeks, we have found...
Neutron stars are one of the most suitable environments for probing physics under extreme states. For example, the quasi-periodic oscillations (QPOs) observed in a giant flare occurred in a strongly magnetized neutron star (magnetar), are carrying crucial information for extracting the neutron star properties. To theoretically explain the observed QPOs in GRB 200415A, we systematically examine...
Based on: Phys. Rev. D 109, 023027 (2024), arXiv:2311.02169
Neutron stars (NSs) can have core densities several times that of the nuclear saturation density. One of the open questions in NS physics is the unknown high-density nuclear matter equation of state (EOS). By considering a number of proposed, phenomenological relativistic mean-field EOSs, we construct theoretical models of NSs....
The launch of the IXPE telescope in late 2021 finally made polarization measurements in the 2-8 keV band a reality, more than 40 years after the pioneering observations of the OSO-8 satellite. In the first two years of operations, IXPE targeted more than 60 sources, including four magnetars, neutron stars with magnetic fields in the petaGauss range. In this presentation I will summarize the...
The magnetic field of a neutron star plays a key role in its evolution and the dynamics of the emission, both electromagnetic and gravitational. Nevertheless the field configuration of these stars is still highly uncertain. In this talk I will review the main issues involved in modelling the magnetic field, and recent advances.
Superluminous supernovae are a class of exceedingly bright transients whose luminosity cannot be comfortably explained by the standard 56Ni-decay picture. The quest for an alternative scenario has pointed at the contribution of a nascent millisecond magnetar and/or at the interaction of the supernova ejecta with a circumstellar medium surrounding the progenitor star; however, some of the...
Magnetars are slowly rotating, young, and isolated neutron stars with surface dipole magnetic fields exceeding the quantum electrodynamic magnetic field limit. They exhibit highly energetic behavior, as in the case of soft-gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs). Recently, they have been studied with paramount interest by almost every modern X-ray telescope. Despite the...
The NICER (Neutron star Interior Composition ExploreR) X-ray telescope on the International Space Station can provide a powerful approach to the magnetar and FRB connections using its large effective area and prompt follow-up observation of transients. Our NICER magnetar and magnetosphere (M&M) science collaboration has observed several transient magnetars and FRB-related phenomena. We...
I will illustrate a new method to search for long transient gravitational wave signals, like those expected from fast spinning newborn magnetars, in interferometric detector data.
Because of the fast frequency variation of these signals, matched filter techniques used for standard semi-periodic persistent signals are computationally unfeasible.
We explored a different approach by means of...
The exceptionally low mass $0.77_{-0.17}^{+0.2} M_{\odot}$ inferred of the central compact object (CCO) XMMU J173203.3--344518 within the SNR HESS J1731--347, of age $\approx 4.5$ kyr, challenges the standard core-collapse scenario of NS formation. The observed (likely post-AGB) star of $\approx 0.6 M_\odot$, at $0.3$ pc from XMMU J1732, also within the SNR, enriches the scenario. To address...
We study numerically a combined gravitational and nonlinear magnetic lensing effect on electromagnetic flux. A magnetar with a dipole magnetic field and background gravitational field is considered to deflect the light rays which passed through its magnetosphere. We assume a square wave front as a grid with the dynamic step. At the nodes of this grid, the rays enter perpendicularly into the...
