- ID:
- ivo://CDS.VizieR/J/AJ/146/104
- Title:
- Dwarf galaxies surface brightness profiles. I.
- Short Name:
- J/AJ/146/104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial surface brightness profiles of spiral galaxies are classified into three types: (I) single exponential, or the light falls off with one exponential to a break before falling off (II) more steeply, or (III) less steeply. Profile breaks are also found in dwarf disks, but some dwarf Type IIs are flat or increasing out to a break before falling off. Here we re-examine the stellar disk profiles of 141 dwarfs: 96 dwarf irregulars (dIms), 26 Blue Compact Dwarfs (BCDs), and 19 Magellanic-type spirals (Sms). We fit single, double, or even triple exponential profiles in up to 11 passbands: GALEX FUV and NUV, ground-based UBVJHK and H{alpha}, and Spitzer 3.6 and 4.5{mu}m. We find that more luminous galaxies have brighter centers, larger inner and outer scale lengths, and breaks at larger radii; dwarf trends with M_B_extend to spirals. However, the V-band break surface brightness is independent of break type, M_B_, and Hubble type. Dwarf Type II and III profiles fall off similarly beyond the breaks but have different interiors and IIs break ~twice as far as IIIs. Outer Type II and III scale lengths may have weak trends with wavelength, but pure Type II inner scale lengths clearly decrease from the FUV to visible bands whereas Type III inner scale lengths increase with redder bands. This suggests the influence of different star formation histories on profile type, but nonetheless the break location is approximately the same in all passbands. Dwarfs continue trends between profile and Hubble types such that later-type galaxies have more Type II but fewer Type I and III profiles than early-type spirals. BCDs and Sms are over-represented as Types III and II, respectively, compared to dIms.
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- ID:
- ivo://CDS.VizieR/J/AJ/151/145
- Title:
- Dwarf galaxies surface brightness profiles. II.
- Short Name:
- J/AJ/151/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this second paper of a series, we explore the B-V, U-B, and FUV-NUV radial color trends from a multi-wavelength sample of 141 dwarf disk galaxies. Like spirals, dwarf galaxies have three types of radial surface brightness profiles: (I) single exponential throughout the observed extent (the minority), (II) down-bending (the majority), and (III) up-bending. We find that the colors of (1) Type I dwarfs generally become redder with increasing radius, unlike spirals which have a blueing trend that flattens beyond ~1.5 disk scale lengths, (2) Type II dwarfs come in six different "flavors", one of which mimics the "U" shape of spirals, and (3) Type III dwarfs have a stretched "S" shape where the central colors are flattish, become steeply redder toward the surface brightness break, then remain roughly constant beyond, which is similar to spiral Type III color profiles, but without the central outward bluing. Faint (-9>M_B_>-14) Type II dwarfs tend to have continuously red or "U" shaped colors and steeper color slopes than bright (-14>M_B_>-19) Type II dwarfs, which additionally have colors that become bluer or remain constant with increasing radius. Sm dwarfs and BCDs tend to have at least some blue and red radial color trend, respectively. Additionally, we determine stellar surface mass density ({Sigma}) profiles and use them to show that the break in {Sigma} generally remains in Type II dwarfs (unlike Type II spirals) but generally disappears in Type III dwarfs (unlike Type III spirals). Moreover, the break in {Sigma} is strong, intermediate, and weak in faint dwarfs, bright dwarfs, and spirals, respectively, indicating that {Sigma} may straighten with increasing galaxy mass. Finally, the average stellar surface mass density at the surface brightness break is roughly 1-2M_{Sun}_pc^-2^ for Type II dwarfs but higher at 5.9M_{Sun}_pc^-2^ or 27M_{Sun}_pc^-2^ for Type III BCDs and dIms, respectively.
- ID:
- ivo://CDS.VizieR/J/A+AS/129/455
- Title:
- Dwarf galaxy candidates around interacting galaxies
- Short Name:
- J/A+AS/129/455
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from the imaging of a sample of 12 interacting galaxies for which we have catalogued all potential dwarf systems in the vicinity of these strongly interacting galaxies. After careful cleaning of the images and applying a restrictive S/N criterion we have identified, measured and catalogued all possible extended objects in each field. On the frames, covering 11.4x10.5arcmins, on the order of 100 non-stellar, faint, extended objects were found around each interacting galaxy. The vast majority (>98%) of these objects had not been previously identified. The number of expected objects in the magnitude range R=18-19.5 exceeds the expected count of background galaxies. This supports the possibility that a density enhancement of extended objects around some interacting galaxies results from the addition of a locally formed dwarf galaxy population.
- ID:
- ivo://CDS.VizieR/J/MNRAS/435/1928
- Title:
- Dwarf galaxy planes in Local Group
- Short Name:
- J/MNRAS/435/1928
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Both major galaxies in the Local Group (LG) are surrounded by thin planes of mostly co-orbiting satellite galaxies, the vast polar structure (VPOS) around the Milky Way (MW) and the Great Plane of Andromeda (GPoA) around M31. We summarize the current knowledge concerning these structures and compare their relative orientations by re-determining their properties in a common coordinate system. The existence of similar, coherent structures around both major LG galaxies motivates an investigation of the distribution of the more distant non-satellite galaxies in the LG. This results in the discovery of two planes (diameters of 1-2Mpc) which contain almost all nearby non-satellite galaxies. The two LG planes are surprisingly symmetric. They are inclined by only 20{deg} relative to the galactic disc of M31, are similarly thin (heights of {approx}60kpc) and have near-to-identical offsets from the MW and from M31. They are inclined relative to each other by 35{deg}. Comparing the plane orientations with each other and with additional features reveals indications for an intimate connection between the VPOS and the GPoA. They are both polar with respect to the MW, have similar orbital directions and are inclined by about 45{deg}+/-7{deg} relative to each other. The Magellanic Stream approximately aligns with the VPOS and the GPoA, but also shares its projected position and line-of-sight velocity trend with a part of the dominating structure of non-satellite dwarf galaxies. In addition, the recent proper motion measurement of M31 indicates a prograde orbit of the MW-M31 system, the VPOS and the GPoA. The alignment with other features such as the Supergalactic Plane and the overdensity in hypervelocity stars are discussed as well. We end with a short summary of the currently proposed scenarios trying to explain the LG galaxy structures as either originating from cosmological structures or from tidal debris of a past galaxy encounter. We emphasize that there currently exists no full detailed model which satisfactorily explains the existence of the thin symmetric LG planes.
- ID:
- ivo://CDS.VizieR/J/AJ/80/972
- Title:
- Dwarf K and M stars at low latitudes
- Short Name:
- J/AJ/80/972
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report 100 dwarf K and M stars found on objective-prism plates taken at low galactic latitudes, mostly in the southern sky. Most stars were recognized from the strength of the sodium D lines, and the majority have known proper motions of 0.1" or more per annum. Ninety-nine of these stars lack previous spectral classification; one lacks previous observation of line emission. Most have below the limits of the DM charts, and for there we provide identification charts.
- ID:
- ivo://CDS.VizieR/J/AJ/77/486
- Title:
- Dwarf K and M stars in Southern hemisphere
- Short Name:
- J/AJ/77/486
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the course of the near-complete Michigan Spectral Survey of the Southern sky, 624 dwarf stars of type K2V and later have been identified. Many of these stars are previously unrecognized as nearby late dwarfs. The plates used are the Curtis Schmidt 10{deg} prism plates taken for the HD reclassification project.
- ID:
- ivo://CDS.VizieR/III/123B
- Title:
- Dwarf K and M stars of small proper motion
- Short Name:
- III/123B
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/PASJ/64/63
- Title:
- Dwarf novae characterization using SDSS colors
- Short Name:
- J/PASJ/64/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have developed a method for estimating the orbital periods of dwarf novae from the Sloan Digital Sky Survey (SDSS) colors in quiescence using an artificial neural network. For typical objects below the period gap with sufficient photometric accuracy, we were able to estimate the orbital periods with accuracy to a 1{sigma} error of 22%. The error of the estimation is worse for systems with longer orbital periods. We have also developed a neural-network-based method for categorical classification. This method has proven to be efficient in classifying objects into three categories (WZ Sge type, SU UMa type, and SS Cyg/Z Cam type), and works for very faint objects to a limit of g=21mag. Using this method, we have investigated the distribution of the orbital periods of dwarf novae from a modern transient survey (Catalina Real-Time Survey).
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/2526
- Title:
- Dwarf novae outbursts properties
- Short Name:
- J/MNRAS/460/2526
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a statistical study of all measurable photometric features of a large sample of dwarf novae during their outbursts and superoutbursts. We used all accessible photometric data for all our objects to make the study as complete and up to date as possible. Our aim was to check correlations between these photometric features in order to constrain theoretical models which try to explain the nature of dwarf novae outbursts. We managed to confirm a few of the known correlations, that is the Stolz and Schoembs relation, the Bailey relation for long outbursts above the period gap, the relations between the cycle and supercycle lengths, amplitudes of normal and superoutbursts, amplitude and duration of superoutbursts, outburst duration and orbital period, outburst duration and mass ratio for short and normal outbursts, as well as the relation between the rise and decline rates of superoutbursts. However, we question the existence of the Kukarkin-Parenago relation but we found an analogous relation for superoutbursts. We also failed to find one presumed relation between outburst duration and mass ratio for superoutbursts. This study should help to direct theoretical work dedicated to dwarf novae.
- ID:
- ivo://CDS.VizieR/J/A+AS/107/365
- Title:
- Dwarfs and subdwarfs IR photometry
- Short Name:
- J/A+AS/107/365
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of a long term programme of broad band JHK photometry, for a sample of 360 late type stars, made at the Observatorio del Teide (Tenerife, Spain) are presented.