scholarly journals The rotation curve, mass, light, and velocity distribution of M31

1970 ◽  
Vol 38 ◽  
pp. 51-60
Author(s):  
J. Einasto ◽  
U. Rümmel
Keyword(s):  
Spectroscopic Data ◽  
Total Mass ◽  
Rotation Curve ◽  
Mass Density ◽  
Major Axis ◽  
Deviation Angle ◽  
Andromeda Galaxy ◽  
The Galaxy ◽  
M 31 ◽  
Central Concentration

A model for the Andromeda galaxy, M 31, has been derived from the available radio, photometric, and spectroscopic data. The model consists of four components – the nucleus, the bulge, the disc, and the flat component.For all components the following functions have been found: the mass density; the mass-to-light ratio; the velocity dispersions in three perpendicular directions (for the plane of symmetry and the axis of the galaxy); the deviation angle of the major axis of the velocity ellipsoid from the plane of symmetry; the centroid velocity (for the plane of symmetry).Our model differs in two points from the models obtained by other authors: the central concentration of mass is higher (in the nucleus the mass-to-light ratio is about 170), and the total mass of the galaxy (200 × 109 solar masses) is smaller. The differences can be explained by different rotation curves adopted, and by attributing more weight to photometric and spectroscopic data in the case of our model.

scholarly journals Longslit spectroscopy of the peculiar Seyfert 2 galaxy HRG 10103

2010 ◽  
Vol 6 ◽  
pp. 11-16
Author(s):  
Paulo C.R. Poppe ◽  
Vera A.F. Martin ◽  
Max Faúndez-Abans ◽  
Mariângela De Oliveira-Abans ◽  
Iranderly F. De Fernandes
Keyword(s):  
Spectroscopic Data ◽  
Rotation Curve ◽  
Abundance Ratio ◽  
Emission Lines ◽  
Physical Parameters ◽  
Narrow Line ◽  
Optical Range ◽  
Peculiar Galaxy ◽  
The Galaxy ◽  
The Continuum

We present the rst optical longslit spectroscopy for the galaxy HRG 10103, an Sa(r) type peculiar galaxy seen face-on with an asymmetrical elliptical structure. The main goal of this work is to provide the spectral classication of the current object using the `traditional' diagnostic diagrams. However, we also present a diagnostic involving the known emission line ratio R23, usually used to estimate the O/H abundance ratio. The idea is to make a better distinction between the narrow-line AGNs and the H II galaxies. The spectra were obtained in two observatories (OPD-LNA/MCT and Gemini-South) and includes some of the most important emission lines for ionization diagnostic. Based on the observed spectra, HRG 10103 is a Seyfert 2 galaxy with typical line-ratios values in the optical range. We have estimated nuclear redshift of z = 0.039. The resulting reddening values as a function of distance from the nucleus are presented too. The errors in the  fluxes were mostly caused by uncertainties in the placement of the continuum level. The rotation curve is typical of spiral disks, rising shallowly and  attening at an observed amplitude of about 200 km s^(-1). Some other physical parameters have been derived whenever possible. The spectroscopic data reduction was carried out using the GEMINI.GMOS package as well as the standard IRAF procedures.

The Rotation Curve from A-F Supergiants

1996 ◽  
Vol 169 ◽  
pp. 703-706
Author(s):  
D. M. Peterson ◽  
D. Slowik
Keyword(s):  
Total Mass ◽  
Rotation Curve ◽  
Galactic Center ◽  
Galactic Rotation ◽  
The Sun ◽  
Critical Information ◽  
New Class ◽  
The Galaxy ◽  
Local Distance

The Galactic rotation law provides critical information for estimating the distribution of mass in the Galaxy, for tying the distance of the Sun from the Galactic center to local distance scales, and, if determined over large enough distances, for estimating the total mass of the system and the amount of nonluminous matter present. Interior to the Sun velocities are well defined by observations of the ISM, particularly HI. These techniques are not available for points exterior to the Sun and we must rely on observations of velocities of objects whose distances can be estimated. Notable among these are the Cepheids (Pont et al 1994) and the combination of CO velocities and OB cluster distances (Brand & Blitz 1993) where the two are found to coexist. Adding a new class of objects, particularly bright, relatively common objects to this effort is of importance.

Revisiting the innermost kinematics of M31 galaxy with the OMM Fabry-Perot interferometer

2019 ◽  
Vol 14 (S353) ◽  
pp. 130-133
Author(s):  
Sié Zacharie Kam ◽  
Claude Carignan ◽  
Michel Marcelin ◽  
Philippe Amram ◽  
Jean Koulidiati
Keyword(s):  
Rotation Curve ◽  
Narrow Band ◽  
Optical Emission ◽  
Emission Lines ◽  
Interference Filters ◽  
Andromeda Galaxy ◽  
Fabry Perot ◽  
The Galaxy ◽  
Data Points ◽  
Made In

AbstractWe present observations on optical emission lines acquired with the scanning Fabry-Perot interferometer of the observatoire du Mont Mégantic, of the Andromeda galaxy (M31). A 765 order Fabry-Perot were used with a fast readout EM-CCD. From data obtained, kinematic maps and data points for the rotation curve of the innermost part of the galaxy are derived. Several dozen of regions have been scanned with the Fabry-Perot interferometer and narrow band interference filters. The central 10’x10’ were scanned with five different filters. Observations have been made in order to get better Hα data for kinematics purposes.

scholarly journals CO in NGC 5055

1987 ◽  
Vol 115 ◽  
pp. 659-660
Author(s):  
L.E.B. Johansson ◽  
R. S. Booth
Keyword(s):  
Velocity Field ◽  
Radial Distribution ◽  
Rotation Curve ◽  
A Priori ◽  
Optical Emission ◽  
Major Axis ◽  
Rotation Curves ◽  
Fitting Procedure ◽  
The Galaxy ◽  
Co Emission

The flocculent spiral galaxy NGC 5055 has been mapped along the major axis in the 12CO (J = 1-0) line using the Onsala 20-m telescope (HPBW = 33″). Figure 1, which gives the spatial velocity diagram of CO emission on the major axis with observed Hα velocities (Kruit and Bosma, 1978) superimposed, seems to imply higher velocities of the regions responsible for the optical emission. Taking into account the cruder spatial resolution of the CO observations, this effect is expected in a region where the rotation curve rises rapidly provided that the CO emission increases toward the centre. Figure 2 shows the rotation velocities for the eastern and western parts of the galaxy separately, as observed in Hα and CO. For CO we only give the portion of the rotation curve which is accurately determined, i.e. where it is relatively flat. The CO velocities in this region agree closely with those observed in HI (Bosma, 1978). These data suggest a difference of 10-20 km s−1 between the Hα and CO velocities at a distance of ∼ 60″ from the centre. The radial distribution of the CO emission, also indicated in Fig. 2, is defined by an iterative fitting procedure to the observed line profiles (see Scoville et al. 1983). This procedure requests an a priori knowledge of the velocity field, here assumed to be defined by the Hα data inside a radius of 60″. However, the shapes of the observed spectra and “best fit” model profiles differ significantly in some cases, again indicating that the Hα velocities do not apply to the molecular gas. The derived radial distribution of the CO emission is dependent on the assumed velocity field; however, the gross characteristics are retained for more feasible rotation curves (i.e. rotation curves giving better fits to the observed profiles).

scholarly journals Orbits of the Magellanic Clouds

1991 ◽  
Vol 148 ◽  
pp. 475-477
Author(s):  
Slobodan Ninkovic ◽  
Miroslav Filipovic
Keyword(s):  
Angular Momentum ◽  
Total Mass ◽  
Rotation Curve ◽  
Magellanic Clouds ◽  
Symmetric Model ◽  
Spherically Symmetric ◽  
Curve Boundary ◽  
The Galaxy ◽  
Spherically Symmetric Model ◽  
Inner Parts

We use a simple, spherically symmetric model for the Galaxy based on the rotation curve for the inner parts. We extrapolate beyond the rotation curve boundary, assuming a dark corona whose total mass is a model parameter. For each mass value assume we calculate the allowed angular-momentum interval for which a cloud is neither tidally disrupted, nor escapes. On the basis of this investigation we reach a conclusion about the expected mass of the Galaxy.

scholarly journals The Rotation Curves of Galaxies

1975 ◽  
Vol 69 ◽  
pp. 331-340 ◽  
Author(s):  
M. S. Roberts
Keyword(s):  
Rotation Curve ◽  
Mass Density ◽  
Rotational Velocity ◽  
Solar Neighborhood ◽  
Optical Measurements ◽  
H Ii Regions ◽  
Rotation Curves ◽  
Surface Mass ◽  
The Galaxy ◽  
Surface Mass Density

Currently available data on rotation curves are reviewed. For curves derived from optical measurements the distribution of the ratios: the last measured point on a rotation curve to the optical radius of the galaxy has a median value of if Reference Catalogue radii are used and if Holmberg radii are used. It is the absence of easily measurable H II regions that so severely limits the extent of these rotation curves. Accordingly, little can be said of the dependence of Vc on R for large R, where R is comparable to a Holmberg radius. The assumption that a rotation curve approaches a Keplerian curve after passing its peak rotational velocity implies a strongly concentrated and limited extent of the mass distribution within a galaxy. This assumption is not supported by 21-cm observations of the velocity field within a galaxy. Because of the greater extent of H I compared to measurable optical (blue) surface brightness, rotation curves may be defined to much larger radii from 21-cm observations. The median value of the above ratio for 14 galaxies is 1.3. At least 7 of these galaxies show an essentially constant rotational velocity at large R, while 5 galaxies have a slowly decreasing Vc(R). For both types of curves, a significant surface mass density at large R is required, and a large (≳ 100) mass-to-luminosity ratio is indicated. Such values are consistent with a late dwarf M star population (the most common type of star in the solar neighborhood) in the outer regions of a galaxy.

scholarly journals Neutral Hydrogen In The Irregular Galaxy Ngc 3Lo9

1966 ◽  
Vol 19 (5) ◽  
pp. 687 ◽  
Keyword(s):  
Radio Telescope ◽  
Total Mass ◽  
Rotation Curve ◽  
Neutral Hydrogen ◽  
Irregular Galaxy ◽  
The Galaxy

The galaxy NGC 3109 was investigated at 21 cm wavelength with the 210 ft radio telescope at Parkes. For a distance d = 2�2 Mpc the total mass of neutral hydrogen is MH = 2�2 X 109 M0 (corrected for self-absorption). The rotation curve has been determined

scholarly journals AGN feedback in a galaxy merger: multi-phase, galaxy-scale outflows with a fast molecular gas blob ∼6 kpc away from IRAS F08572+3915

2020 ◽  
Vol 635 ◽  
pp. A47 ◽  
Author(s):  
R. Herrera-Camus ◽  
A. Janssen ◽  
E. Sturm ◽  
D. Lutz ◽  
S. Veilleux ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Total Mass ◽  
Formation Rate ◽  
Major Axis ◽  
Molecular Gas ◽  
Gas Phases ◽  
The Galaxy ◽  
Outflow Rate ◽  
Multi Phase

To understand the role that active galactic nuclei (AGN) feedback plays in galaxy evolution, we need in-depth studies of the multi-phase structure and energetics of galaxy-wide outflows. In this work, we present new, deep (∼50 h) NOEMA CO(1-0) line observations of the molecular gas in the powerful outflow driven by the AGN in the ultra-luminous infrared galaxy IRAS F08572+3915. We spatially resolve the outflow, finding that its most likely configuration is a wide-angle bicone aligned with the kinematic major axis of the rotation disk. The molecular gas in the wind reaches velocities up to approximately ±1200 km s−1 and transports nearly 20% of the molecular gas mass in the system. We detect a second outflow component located ∼6 kpc northwest from the galaxy moving away at ∼900 km s−1, which could be the result of a previous episode of AGN activity. The total mass and energetics of the outflow, which includes contributions from the ionized, neutral, and warm and cold molecular gas phases, is strongly dominated by the cold molecular gas. In fact, the molecular mass outflow rate is higher than the star formation rate, even if we only consider the gas in the outflow that is fast enough to escape the galaxy, which accounts for ∼40% of the total mass of the outflow. This results in an outflow depletion time for the molecular gas in the central ∼1.5 kpc region of only ∼3 Myr, a factor of ∼2 shorter than the depletion time by star formation activity.

scholarly journals The Asteroid Belt as the Consequence of Resonance Density Convergence from Solar Velocity around the Galaxy and Universal Dynamic Pressure

2014 ◽  
Vol 34 ◽  
pp. 73-79 ◽  
Author(s):  
Michael A. Persinger ◽  
David A.E. Vares
Keyword(s):  
Solar System ◽  
Total Mass ◽  
Mass Density ◽  
Dynamic Pressure ◽  
Critical Mass ◽  
Critical Density ◽  
Asteroid Belt ◽  
Chemical Characteristics ◽  
Quantitative Evidence ◽  
The Galaxy

The velocity of the solar system around the galaxy as it moves through universal dynamic pressure of about 0.15 nPa results in a critical mass density of 1.5 protons per cc. Interplanetary measurements indicate this density occurs within the space occupied by asteroids. Quantitative evidence is offered that the matter in asteroid space failed to accrete into a planet because of the disruptive resonance between universal dynamic pressure and the velocity of the system. The model may accommodate the chemical characteristics of the different regions of the asteroid belt and the marked difference in planetary characteristics above (the inner planets) and below (the “gas giants”) the critical density. The energy accumulated within the functional toroidal space between Mars and Jupiter since the formation of the solar system is equivalent to the total mass of asteroids. If energy is still emerging within this region then the probability of non-traditional disruption of orbits for certain masses of asteroids may have significant impact. Specific frequencies that should show enhanced power based upon these calculations are derived.

scholarly journals A comparison of dynamical models of the Andromeda Nebula and the Galaxy

1970 ◽  
Vol 38 ◽  
pp. 61-68
Author(s):  
V. C. Rubin ◽  
W. K. Ford
Keyword(s):  
Rotation Curve ◽  
Neutral Hydrogen ◽  
Radial Velocities ◽  
H Ii Regions ◽  
Dynamical Models ◽  
Mass Model ◽  
The Galaxy ◽  
Andromeda Nebula ◽  
M 31

(1) From new radial velocities of 67 H II regions in M 31, rotational velocities and a mass model of M 31 are derived, and compared with the rotation curve and Schmidt mass model of our galaxy. (2) It is shown that in M 31 the distribution of H II regions as identified by Baade agrees with the distribution of neutral hydrogen determined from 21-cm observations. Also, the rotation curve derived from the H II velocities outside of the nucleus is similar to the rotation curve derived from 21-cm H I observations.

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