Using 16,000-channel spectrometers at the Nobeyama 45-m radio telescope, we have found HO maser emission in the nucleus of the galaxy NGC4258, offset by 卤 1,000 km sfrom the motion of the nucleus itself. This is much higher than the typical velocities of galactic masers (less than a ...
4258 obtained with the Gemini telescope are combined with existing data from the literature to measure the radial oxygen abundance gradient in this galaxy. The [O III]λ4363 auroral line was detected in four of the outermost targets (17-22 kpc from the galaxy center), allowing a determination...
M106(也称为NGC 4258)是一个位于猎犬座的螺旋星系,由法国天文学家皮埃尔·梅香(Pierre Méchain)于1781年所发现,它也是一个赛弗特星系(Seyfert galaxies),由于星系发射出X射线,意谓著有一个超大质量黑洞位于星系的核心。M106 - Seyfert II Spiral Galaxy in Canes Venatici...
We present a Spitzer Infrared Spectrograph (IRS) map of H2 emission from the nearby galaxy NGC 4258 (Messier 106). The H2 emission comes from 9.4E6 Msun of warm molecular hydrogen heated to 240-1040 K in the inner anomalous arms, a signature of jet interaction with the galaxy disk. The ...
The remarkable continuum arms in the spiral galaxy NGC 4258 are suggestive of some form of ejection from the nucleus of this galaxy (Van der Kruit, Oort and Mathewson, 1972). To summarize the observations (see Oort, Figure 2, this volume), the “anomalou
The water maser in the mildly active nucleus in the nearby galaxy NGC4258 traces a thin, nearly edge-on, subparsec-scale Keplerian disk. Using the technique of very long baseline interferometry, we have detected the proper motions of these masers as they sweep in front of the central black...
In view of the apparent association of H_2_O megamaser emission with an ultra-compact nuclear structure in NGC4258 and other sources, we speculate that the presence of H_2_O megamasers is directly related to this ultra-compact structure, rather than to the galaxy's infrared luminosity. Thus...
We present an X-ray study of the low-luminosity active galactic nucleus (AGN) in NGC 4258 using data from Suzaku, XMM-Newton, and the Swift/Burst Alert Telescope survey. We find that signatures of X-ray reprocessing by cold gas are very weak in the spectrum of this Seyfert-2 galaxy; ...
to NGC4258 and i s is the disk inclination. Because the high-velocity masers lie in the plane of the sky, they should to first order remain stationary as the disk rotates. The systemic masers, on the other hand, are positioned along the near edge of the disk and amplify the backgrou...
Galaxies: Individual: NGC Number: NGC 4258In a previous paper (Maoz et al. 1999), we reported a Hubble Space Telescope (HST) Cepheid distance to the galaxy NGC 4258 obtained using the calibrations and methods then standard for the Key Project on the Extragalactic Distance Scale. Here, we ...