ترغب بنشر مسار تعليمي؟ اضغط هنا

The pseudobulge of NGC 1292

53   0   0.0 ( 0 )
 نشر من قبل Lorenzo Morelli
 تاريخ النشر 2008
  مجال البحث فيزياء
والبحث باللغة English
 تأليف L. Morelli




اسأل ChatGPT حول البحث

The photometric and kinematic properties of Sb NGC 1292 suggest it hosts a pseudobulge. The properties of the stellar population of such a pseudobulge are consistent with a slow buildup within a scenario of secular evolution.

قيم البحث

اقرأ أيضاً

Supermassive black holes launching plasma jets at close to speed of light, producing gamma-rays, have ubiquitously been found to be hosted by massive elliptical galaxies. Since elliptical galaxies are generally believed to be built through galaxy mer gers, active galactic nuclei (AGN) launching relativistic jets are associated to the latest stages of galaxy evolution. We have discovered a pseudo-bulge morphology in the host galaxy of the gamma-ray AGN PKS 2004-447. This is the first gamma-ray emitter radio loud AGN found to be launched from a system where both black hole and host galaxy have been actively growing via secular processes. This is evidence for an alternative black hole-galaxy co-evolutionary path to develop powerful relativistic jets that is not merger-driven.
We report the discovery of KMT-2018-BLG-1292Lb, a super-Jovian $M_{rm planet} = 4.5pm 1.3,M_J$ planet orbiting an F or G dwarf $M_{rm host} = 1.5pm 0.4,M_odot$, which lies physically within ${cal O}(10,pc)$ of the Galactic plane. The source star is a heavily extincted $A_Isim 5.2$ luminous giant that has the lowest Galactic latitude, $b=-0.28^circ$, of any planetary microlensing event. The relatively blue blended light is almost certainly either the host or its binary companion, with the first explanation being substantially more likely. This blend dominates the light at $I$ band and completely dominates at $R$ and $V$ bands. Hence, the lens system can be probed by follow-up observations immediately, i.e., long before the lens system and the source separate due to their relative proper motion. The system is well characterized despite the low cadence $Gamma=0.15$--$0.20,{rm hr^{-1}}$ of observations and short viewing windows near the end of the bulge season. This suggests that optical microlensing planet searches can be extended to the Galactic plane at relatively modest cost.
We present a systematic study of the Supernova Remnant (SNR) populations in the nearby galaxies NGC 45, NGC 55, NGC 1313, and NGC 7793 based on deep Ha and [S II] imaging. We find 42 candidate and 54 possible candidate SNRs based on the [S II] / Ha > 0.4 criterion, 84 of which are new identifications. We derive the Ha and the joint [S II]-Ha luminosity functions after accounting for incompleteness effects. We find that the Ha luminosity function of the overall sample is described with a skewed Gaussian with a mean equal to log(LHa / 10^(36) erg s^(-1)) = 0.07 and m(log(LHa / 10^(36) erg s^(-1)))) = 0.58. The joint [S II]-Ha function is parameterized by a skewed Gaussian along the log([S II] / 10^(36) erg s^(-1)) = 0.88 x log(LHa / 10^(36) erg s^(-1)) - 0.06 line and a truncated Gaussian with m(log(L[S II] / 10^(36))) = 0.024 and s(log(L[S II] / 10^(36))) = 0.14, on its vertical direction. We also define the excitation function as the number density of SNRs as a function of their [S II]/Ha ratios. This function is represented by a truncated Gaussian with a mean at -0.014. We find a sub-linear [S II]-Ha relation indicating lower excitation for the more luminous objects.
Star-forming galaxies are rich reservoirs of dust, both warm and cold. But the cold dust emission is faint alongside the relatively bright and ubiquitous warm dust emission. Recently, evidence for a very cold dust component has also been revealed via millimeter/submillimeter photometry of some galaxies. This component, despite being the most massive of the three dust components in star-forming galaxies, is by virtue of its very low temperature, faint and hard to detect together with the relatively bright emission from warmer dust. Here we analyze the dust content of a carefully selected sample of four galaxies detected by IRAS, WISE, and SPT, whose spectral energy distributions (SEDs) were modeled to constrain their potential cold dust content. Low-frequency radio observations using the GMRT were carried out to segregate cold dust emission from non-thermal emission in millimeter/submillimeter wavebands. We also carried out AstroSat/UVIT observations for some galaxies to constrain their SED at shorter wavelengths so as to enforce energy balance for the SED modeling. We constructed their SEDs across a vast wavelength range (extending from ultraviolet to radio frequencies) by assembling global photometry from GALEX FUV+NUV, UVIT, Johnson BRI, 2MASS, WISE, IRAC, IRAS, AKARI, ISOPHOT, Planck HFI, SPT, and GMRT. The SEDs were modeled with CIGALE to estimate their basic properties, in particular to constrain the masses of their total and very cold dust components. Although the galaxies dust masses are dominated by warmer dust, there are hints of very cold dust in two of the targets, NGC 7496 and NGC 7590.
94 - O.K. Silchenko 2003
The central regions of the three brightest members of the Leo I galaxy group -- NGC 3368, NGC 3379, and NGC 3384 -- are investigated by means of 2D spectroscopy. In all three galaxies we have found separate circumnuclear stellar and gaseous subsystem s -- more probably, disks -- whose spatial orientations and spins are connected to the spatial orientation of the supergiant intergalactic HI ring reported previously by Schneider et al. (1983) and Schneider (1985, 1989). In NGC 3368 the global gaseous disk seems also to be inclined to the symmetry plane of the stellar body, being probably of external origin. Although the rather young mean stellar age and spatial orientations of the circumnuclear disks in NGC 3379, NGC 3384, and NGC 3368 could imply their recent formation from material of the intergalactic HI cloud, the time scale of these secondary formation events, of order 3 Gyr, does not support the collision scenario of Rood & Williams (1985), but is rather in line with the ideas of Schneider (1985, 1989) regarding tidal interactions of the galaxies with the HI cloud on timescales of the intergroup orbital motions.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا