... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2001 January 15 . Billows of Smog in the Outer Galaxy . ... Explanation: Our Galaxy is filled with gas . ... The above wide-angle radio CO image shows the incredibly diverse structures that the molecular interstellar medium forms. ... About APOD | ...

M1 image More About M1 Nice Color Picture . ... M16 image More About M16 HST image . ... M31 image More About M31 Nice Color Picture . ... M42 image ; M43 image More About M42/43 Nice Color CCD Picture . M51 image More About M51 Color Image of M51 M51 Supernova . M57 image More About M57 Nice Color CCD Picture Very Deep M57 Image . ... M81 image More About M81 M81 Supernova Ultraviolet Image of M81 More about Ultraviolet Imaging . M82 image More About M82 M82 False Color M82 True Color . ...

The Seyfert-2 NGC 7674: . ... As part of a larger project to study Luminous and Ultra-Luminous IR Galaxies in both H I absorption and radio continuum at high resolution, NGC 7674 was observed using the VLBA, the phased VLA, and the 305-m Arecibo radio telescope. ... Figure 1 shows a moderate resolution continuum image of the innermost 1 kpc region of NGC 7674 at 1.38 GHz and 20 milliarcsecond (mas) resolution. ... No absorption is detected toward the components J, W, and SW. ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

... We present a new technique to segregate old and young stellar populations in galactic spectra using machine learning methods. We used an ensemble of classifiers, each classifier in the ensemble specializes in young or old populations and was trained with locally weighted regression and tested using ten-fold cross-validation. ... In this work we propose a Machine Learning (ML) method to determine the age of stellar populations in synthetic galactic spectra. ... Combine results in an ensemble. ...

... A radio galaxy is a galaxy that emits an unusually big amount of energy at radio wavelengths. ... Inside of each galaxy with an active nucleus (radio galaxies are among them) there must be a system of a "central machine" responsible for the colossal amount of the emitted energy from radio to gamma ranges. ... Sometimes a radio source in an active galaxy may flare again if the needed conditions appear (a new portion of matter would fall into the furnace of the "central machine"). ...

We present new images (ground-based optical and mid-infrared [MIR] from the Spitzer Space Telescope) and spectra (from Spitzer) of the archetypal starburst galaxy M82. The Spitzer data show that the MIR emission extends at least 6 kpc along the minor axis of the galaxy. ... The colors of the MIR emission and the spectra indicate that there is a strong component of aromatic feature emission (the MIR features commonly attributed to polycyclic aromatic hydrocarbons). ... ADS Citation Query . ...

... The galaxy NGC 253 is a well-known nearby spiral galaxy showing numerous peculiar features (e.g. a nuclear ring, gas outflow, a bar, and a warp) which we study using tracers of the different gas phases. ... Whereas the X-rays trace the hottest gas component, the Halpha emission, e.g., shows the distribution of the ionized gas at several thousand Kelvin. ... Keywords. galaxies: individual (NGC 253) - galaxies: starburst. HI in NGC 253 . ... Halpha in NGC 253 . ...

... A rare type of galaxy known as a Polar Ring , NGC 4650A is composed of an old central group of stars and a young ring of stars rotating farther out. ... Polar Ring Galaxies allow astronomers to estimate the amount of dark matter in galaxies by measuring the rotation rate of the highly extended ring. ... Publications with keywords: ring galaxy - polar ring - dark matter - ring . Publications with words: ring galaxy - polar ring - dark matter - ring . ... Polar Ring Galaxy NGC 660 . ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. September 22, 1998 . M61: Virgo Spiral Galaxy . ... Explanation: M61 is a barred spiral galaxy located in the nearby Virgo Cluster of Galaxies . Visible in M61 are a host of features common to spiral galaxies : bright spiral arms , a central bar , dust lanes , and bright knots of stars. ... About APOD > . ...

... Here some data observed on the 6m telescope with IFP installed in the OLD focal reducer are presented. ... Mkn 3: velocity field . ... NGC 5252: [OIII] image . ... NGC 5252 was observed 23 Feb. 1998 in the [OIII]5007 emission line with CCD TK1024 as detector. ... We observed the ionized gas velocity fields of the spiral galaxies with two purpose. ... Restored velocity field of NGC 157 in the reference frame rotating with the pattern speed overlaid on the Ha image of the galaxy . ... NGC 4100 . ...

Next: Transparency of the Stochastic Up: Model of the Galaxy Previous: Frequency distribution of galactic . ... The parameters of the model resulted from a numerical fitting of various data, such as the observed distribution of the young star population and neutral hydrogen, the density of population II stars in the vicinity of the Sun, the galactic rotation curve and the dynamics and distribution of globular clusters   and dwarf irregular satellites of the Galaxy. ...

... Magnetic fields, subatomic particles, etc., traveling in different directions fill the universe. Do they deflect or otherwise affect one another? If so, isnт??t the information we get from them distorted? ... Neutrino astronomy, which is still in its infancy, is attractive because neutrinos interact so weakly with matter that few of these distorting effects occur. Get instant access to subscriber content on Astronomy.com! ...

... Archive for May 2009 . ... As discussed in systematic errors, astronomers, like physicists, show their error components in two additive terms; statistical error + systematic error. ... Continue reading ?[ ... Tags: additive , bias , law of total variance , MADS , mathematical statistics , mean integrated square error , mean square error , MISE , mse , probability theory , variance . Category: Algorithms , Data Processing , Jargon , News , Stat , Uncertainty | Comment . ... Category: Misc | ...

Next: The stage and Up: The ESO Red Sky Previous: Artefacts . Fig. 3 shows the distribution of stars. The most striking feature is the rapid steepening of the density gradient towards the Milky Way region at the right and left hand edges of the total field, apparent from the dramatic change in colour in this false colour presentation. Noticable changes in star density across even short distances are indicated by colour changes within individual plates. ... Fig. ...

Catalogue of agn classification . HyperLeda home | Documentation | ... This catalogue (table a109 in the database) presents the compilation of the activity classification of objects. ... AGNCLASS . ... Have very high luminosities (Mabs<-23) and broad emission lines (FWHM=5,000- 30,000km/s) with a large red-shift ( VCV-12 ). ... Broad-line Seyfert 1. Have broad permitted Balmer HI lines (FWHM=1000-10000km/s, typical is 2000-6000km/s) and narrow forbidden lines (FWHM=300-1000km/s). ...

The Experiment: What controls the formation of stars? Galaxies form stars at very different rates: ? availability of raw material (gas)? ? ... Observe all the components of a galaxy gas in various forms, dust etc… . An interacting galaxy . Galaxies are complicated physical systems with not only stars, but also gas in various states, dust and radiation . ... Previous slide . Next slide . Back to first slide . ...

Authors: V.A. Marsakov , T.V. Borkova , . ... It is shown that general populations of globular clusters and metal-poor field stars are components at least of three subsystems occupying different volumes in the Galaxy. The thick disk and proto-disk subsystems are genetically associated with the Galaxy. ... It is argued that heavy-element enrichment and the collapse of the proto-galactic medium occurred mainly in the period between the formation of the proto-disk halo and thick disk subsystems. ...

home education > activities . ... Quick math activity that asks students to calculate scale models of a binary star system with a black hole in it. [h] . ... Students use a radiometer and a light bulb with a dimmer switch to make connections between the temperature, color, and radiation output of a star. ... This demonstration, similar to the above, from the Exploratorium Snack-book of science activities, lets students demonstrate how molecules scatter light and change the colors of the beam. [m,h] . ...

... GSAOI Home . ... Science . ... For example, among the Milky Way's dE companions we see systems with dominant old populations, systems with minor intermediate-age (age ~ 2 to 10 Gyr) components, and systems where the intermediate-age component dominates the old stars. ... This variety of star formation histories is not restricted to the Galaxy's companions. ... To make progress in understanding the processes that govern dwarf galaxy evolution, we need to study systems beyond the Local Group. ...