Scenarios for GCRT J1745-3009

I discuss several scenarios to explain properties of the radio transient source GCRT J1745-3009. Namely, a highly magnetized neutron star on the propeller or georotator stage, a transient propeller, and an ejector in a binary system are discussed. Simple populational estimates favor the transient propeller model.Comment: 8 pages, no figures, Talk at the conference "VA100 Evolution of Cosmic Objects Through Their Physical Activity", Yerevan, Armenia 2008. Subm. to the proceeding

Magneto-rotational and thermal evolution of young neutron stars

After a brief review of population synthesis of close-by cooling neutron stars, I focus on the interpretation of dichotomy of spin periods of near-by coolers. The existence of two well separated groups -- short period ($\sim$0.1-0.3 s) radio pulsars and long period ($\sim$3-10 s) radio quiet sources, aka the Magnificent seven, -- can not be easily explained in unified models developed recently (Popov et al. 2010, Gull{\'o}n et al. 2014). I speculate that the most natural solution of the problem can be in bimodal initial magnetic field distribution related to the existence of an additional mechanism of field generation in magnetars.Comment: 6 pages, proceedings of STARS201

On the mechanism of low-mass compact object formation

We suggest that low-mass compact objects (hadron stars, quark stars) with $M<1 M_{\odot}$ can appear only due to fragmentation of rapidly rotating proto-neutron stars. Such low-mass stars receive large kicks due to an explosion of a lighter companion in a pair of fragments, or due to dynamical ejection of one of the lighter components in the case when three bodies are formed. As far as low-mass compact objects are expected to be slowly cooling in all popular models of thermal evolution possible candidates are expected to be found among hot high velocity sources.Comment: 4 pages, no figure

Old isolated neutron stars

In this poster I briefly review several articles on astrophysics of old isolated neutron stars, which were published in 1994-99 by my co-authors and myself.Comment: 9 pages, 9 PostScript figure

Close by Compact Objects and Recent Supernovae in the Solar Vicinity

I discuss young close-by compact objects, recent supernovae in the solar neighbourhood, and point to their connection with cosmic ray studies. Especially the role of the Gould Belt is underlined.Comment: 12 pages, proceedings of the International School of Cosmic Ray Astrophysics, 14th Course: "Neutrinos and Explosive Events in the Universe

Origin of magnetars in binary systems

I review several scenarios of magnetar formation in binary systems via spin-up of a progenitor due to interaction with its companion. Mostly, these evolutionary channels lead to formation of isolated magnetars, and indeed, all well-established sources of this class are single objects. However, some binaries can survive, and several candidates to accreting magnetars have been proposed. I discuss this issue, and conclude that new accretion models can explain properties of the proposed candidates without large magnetic field in correspondence with models of magnetic field evolution.Comment: 10 pages, no figures, based on a talk presented at "Ioffe Workshop on GRBs and other transient sources: 20 Years of Konus-Wind Experiment", subm. to a special issue of Astron. Astrophys. Tran

Origin of magnetar-scale crustal field in PSR J1852+0040 and "frozen" magnetars

We discuss the origin of strong crustal magnetic field in one of central compact objects (CCOs) --- a neutron star PSR J1852+0040 in the supernova remnant Kes 79. Taking into account its relatively long present day spin period we conclude that the field could not be generated via a dynamo mechanism. If this neutron star indeed is a magnetar with field submerged during a strong fall-back episode, then it argues against the dynamo field origin in magnetars. Otherwise, Kes 79 is not a close relative of normal magnetars. A discovery of an anti-magnetar with a millisecond period and strong crustal field identifiable, for example, due to large pulse fraction, would be the proof of the dynamo field origin. Existence of such sources is in correspondence with the present standard picture of neutron star unification. However, the fraction of magnetars with submerged fields can be small --- few percent of the total number of CCOs.Comment: 4 pages, accepted for publication in PAS

A parameter to quantify dynamics of a researcher's scientific activity

I propose the coefficient, $t_h$, and its modification $N_t$ which in a simple way reflect dynamics of scientific activity of an individual researcher. I determine $t_h$ as a time period (from some moment in the past till the present moment) during which papers responsible for 1/2 of the total citation index were published. Parameter $N_t$ represents average of the citation index over this period: $N_t={\mathrm{C.I.}}/2t_h$.Comment: 4 pages including 2 figures, article styl

The Zoo of Neutron Stars

In these lecture notes I briefly discuss the present day situation and new discoveries in astrophysics of neutron stars focusing on isolated objects. The latter include soft gamma repeaters, anomalous X-ray pulsars, central compact objects in supernova remnants, the Magnificent seven, and rotating radio transients. In the last part of the paper I describe available tests of cooling curves of neutron stars and discuss different additional constraints which can help to confront theoretical calculations of cooling with observational data.Comment: 12 pages, no figures. To appear in the proceedings of the summer school "Dense Matter In Heavy Ion Collisions and Astrophysics" in a separate volume of Particles and Nuclei, Letter

What is the nature of the central compact X-ray source in the supernova remnant RCW 103

In this poster I discuss the nature of the compact X-ray source in the center of the supernova remnant RCW 103. Several models, based on the accretion onto a compact object such as a neutron star or a black hole (isolated or binary), are analyzed. I show that it is more likely that the central X-ray source is an accreting neutron star than an accreting black hole. I also argue that models of a disrupted binary system consisting of an old accreting neutron star and a new one observed as a 69-ms X-ray and radio pulsar are most favored.Comment: 8 pages, no figures, to be presented as a poster at the conference "Non-accelerator particle astrophysics" 29 June - 10 July 1998, Trieste, Italy. In the replaced version a short note about earlier discussion by Torii et al. was adde