We report the identification of 2MASX J032441.19ϩ341045.9 (hereafter 2MASX J0324ϩ3410) with an appealing object that shows the dual properties of both a narrow-line Seyfert 1 galaxy (NLS1) and a blazar. Its optical spectrum, which has a Hb line width of about 1600 km s Ϫ1 (FWHM), an [O iii]-to-Hb line ratio of Ӎ0.12, and strong Fe ii emission, clearly fulfills the conventional definition of NLS1s. On the other hand, 2MASX J0324ϩ3410 also exhibits some behavior that is characteristic of blazars, including a flat radio spectrum above 1 GHz, a compact core plus a one-sided jet structure on milliarcsecond scale at 8.4 GHz, highly variable fluxes in the radio, optical, and X-ray bands, and a possible detection of TeV g-ray emission. On its optical image, obtained with the HST WFPC2, the active nucleus is displaced from the center of the host galaxy, which exhibits an apparent one-armed spiral structure extended to 16 kpc. The remarkable hybrid behavior of this object presents a challenge to current models of NLS1s and g-ray blazars.
We report the discovery of superstrong, fading, high-ionization iron line emission in the galaxy SDSS J095209.56ϩ214313.3 (SDSS J0952ϩ2143 hereafter), which must have been caused by an X-ray outburst of large amplitude. SDSS J0952ϩ2143 is unique in its strong multiwavelength variability; such a broadband emissionline and continuum response has not been observed before. The strong iron line emission is accompanied by unusual Balmer line emission with a broad base, narrow core, and double-peaked narrow horns, and strong He ii emission. These lines, while strong in the SDSS spectrum taken in 2005, have faded away significantly in new spectra taken in 2007 December. Comparison of SDSS, 2MASS, GALEX, and follow-up GROND photometry reveals variability in the NUV, optical, and NIR band. Taken together, these unusual observations can be explained by a giant outburst in the EUV-X-ray band, detected even in the optical and NIR. The intense and variable iron, helium, and Balmer lines represent the "light echo" of the flare, as it traveled through circumnuclear material. The outburst may have been caused by the tidal disruption of a star by a supermassive black hole. Spectroscopic surveys such as SDSS are well suited to detect emission-line light echoes of such rare flare events. Reverberationmapping of these light echoes can then be used as a new and efficient probe of the physical conditions in the circumnuclear material in nonactive or active galaxies.
In this work, we interpreted the high braking index of PSR J1640−4631 with a combination of the magnetodipole radiation and dipole magnetic field decay models. By introducing a mean rotation energy conversion coefficient z , the ratio of the total high-energy photon energy to the total rotation energy loss in the whole life of the pulsar, and combining the pulsar's high-energy and timing observations with a reliable nuclear equation of state, we estimate the pulsar's initial spin period, P 17 44 0~( -) ms, corresponding to the moment of inertia I 0.8 2.1 10 45( -) g cm 2 .Assuming that PSR J1640−4631 has experienced a long-term exponential decay of the dipole magnetic field, we calculate the true age t age , the effective magnetic field decay timescale D t , and the initial surface dipole magnetic field at the pole B 0 p ( ) of the pulsar to be 2900−3100 yr, 1.07 2 10 5 ( ) yr, and 1.84 4.20 10 13 ( -) G, respectively. The measured braking index of n 3.15 3 = ( ) for PSR J1640−4631 is attributed to its long-term dipole magnetic field decay and a low magnetic field decay rate, dB dt 1.66 3.85 10 p 8-( -) G yr −1 . Our model can be applied to both the high braking index (n 3 > ) and low braking index (n 3 < ) pulsars, tested by the future polarization, timing, and high-energy observations of PSR J1640−4631.
We report the discovery of a dwarf Seyfert 1 active galactic nucleus (AGN) with a candidate intermediate-mass black hole hosted by the dwarf galaxy SDSS J160531.84+174826.1 at z = 0.032. A broad component of the Hα line with FWHM=781km s −1 is detected in its optical spectrum, and a bright, point-like nucleus is evident from a HST imaging observation. Non-thermal X-ray emission is also detected from the nucleus. The black hole mass, as estimated from the luminosity and width of the broad Hα component, is about 7 × 10 4 M ⊙ . The host galaxy appears to be a disk galaxy with a boxy bulge or nuclear bar; with an absolute magnitude of M R = −17.8, it is among the least luminous host galaxies ever identified for a Seyfert 1.
By introducing Dirac's δ-function in superhigh magnetic fields, we deduce a general formula for the pressure of degenerate and relativistic electrons, P e , which is suitable for superhigh magnetic fields, discuss the quantization of Landau levels of electrons, and consider the quantum electrodynamic(QED) effects on the equations of states (EOSs) for different matter systems. The main conclusions are as follows: the stronger the magnetic field strength, the higher the electron pressure becomes; compared with a common radio pulsar, a magnetar could be a more compact oblate spheroid-like deformed neutron star due to the anisotropic total pressure; and an increase in the maximum mass of a magnetar is expected because of the positive contribution of the magnetic field energy to the EoS of the star. Since this is an original work in which some uncertainties could exist, modifications and improvements of our theory should be considered in our future studies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.