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3861. Triangulum-Andromeda stellar properties
ID:
ivo://CDS.VizieR/J/ApJ/793/62
Title:
Triangulum-Andromeda stellar properties
Short Name:
J/ApJ/793/62
Date:
21 Oct 2021
Publisher:
CDS
Description:
As large-scale stellar surveys have become available over the past decade, the ability to detect and characterize substructures in the Galaxy has increased dramatically. These surveys have revealed the Triangulum-Andromeda (TriAnd) region to be rich with substructures in the distance range 20-30 kpc, and the relation of these features to each other, if any, remains unclear. An exploration using Two Micron All Sky Survey (2MASS) photometry reveals not only the faint sequence in M giants detected by Rocha-Pinto et al. (2004ApJ...615..732R) spanning the range 100{deg}<l<160{deg} and -50{deg}<b<-15{deg}, but, in addition, a second, brighter and more densely populated sequence. These sequences are likely associated with the distinct main sequences (MSs) discovered (and labeled TriAnd1 and TriAnd2) by Martin et al. (2007ApJ...668L.123M) in an optical survey in the direction of M31, where TriAnd2 is the optical counterpart of the fainter red giant branch (RGB)/asymptotic giant branch sequence of Rocha-Pinto et al. Here, the age, distance, and metallicity ranges for TriAnd1 and TriAnd2 are estimated by simultaneously fitting isochrones to the 2MASS RGB tracks and the optical MS/MS turn-off features. The two populations are clearly distinct in age and distance: the brighter sequence (TriAnd1) is younger (6-10 Gyr) and closer (distance of ~15-21 kpc), whereas the fainter sequence (TriAnd2) is older (10-12 Gyr) and at an estimated distance of ~24-32 kpc. A comparison with simulations demonstrates that the differences and similarities between TriAnd1 and TriAnd2 can simultaneously be explained if they represent debris originating from the disruption of the same dwarf galaxy, but torn off during two distinct pericentric passages.
3862. Triplets of galaxies in the SDSS-DR7
ID:
ivo://CDS.VizieR/J/MNRAS/421/1897
Title:
Triplets of galaxies in the SDSS-DR7
Short Name:
J/MNRAS/421/1897
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a new catalogue of galaxy triplets derived from the Sloan Digital Sky Survey (SDSS) Data Release 7. The identification of systems was performed considering galaxies brighter than M_r_=-20.5 and imposing constraints over the projected distances, radial velocity differences of neighbouring galaxies and isolation. To improve the identification of triplets, we employed a data pixelization scheme, which allows us to handle large amounts of data as in the SDSS photometric survey. Using spectroscopic and photometric data in the redshift range 0.01<=z<=0.40, we obtain 5901 triplet candidates. We have used a mock catalogue to analyse the completeness and contamination of our methods.
3863. [TT2009] 25 vicinity VI photometry
ID:
ivo://CDS.VizieR/J/A+A/629/L2
Title:
[TT2009] 25 vicinity VI photometry
Short Name:
J/A+A/629/L2
Date:
21 Oct 2021
Publisher:
CDS
Description:
Dwarf galaxies are key objects for small-scale cosmological tests like the abundance problems or the planes-of-satellites problem. A crucial task is therefore to get accurate information for as many nearby dwarf galaxies as possible. Using extremely deep, groundbased V and i-band Subaru Suprime Cam photometry with a completeness of i=27mag, we measure the distance of the dwarf galaxy [TT2009] 25 using the tip of the red giant branch (RGB) as a standard candle. This dwarf resides in the field around the Milky Way-analog NGC891. Using a Bayesian approach, we measure a distance of 10.28Mpc, which is consistent with the distance of NGC891, and thus confirm it as a member of NGC891. The dwarf galaxy follows the scaling relations defined by the Local Group dwarfs. We do not find an extended stellar halo around [TT2009] 25. In the small field of view of 100kpc covered by the survey, only one bright dwarf galaxy and the giant stream are apparent. This is comparable to the Milky Way, where one bright dwarf resides in the same volume, as well as the Sagittarius stream - excluding satellites which are farther away but would be projected in the line-of-sight. It is thus imperative to survey for additional dwarf galaxies in a larger area around NGC891 to test the abundance of dwarf galaxies and compare this to the number of satellites around the Milky Way.
3864. Tucana dSph CMD and star formation history
ID:
ivo://CDS.VizieR/J/A+A/630/A116
Title:
Tucana dSph CMD and star formation history
Short Name:
J/A+A/630/A116
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report a new star formation history for the Tucana dwarf spheroidal galaxy, obtained from a new look at a deep HST/ACS colour-magnitude diagram. We combined information from the main sequence turn-off and the horizontal branch to resolve the ancient star formation rates on a finer temporal scale than previously possible. We show that Tucana experienced three major phases of star formation, two very close together at ancient times and the last one ending between 6 and 8 Gyr ago. We show that the three discrete clumps of stars on the horizontal branch are linked to the distinct episodes of star formation in Tucana. The spatial distribution of the clumps reveals that each generation of stars presents a higher concentration than the previous one. The simultaneous modelling of the horizontal branch and the main sequence turn-off also allows us to measure the amount of mass lost by red giant branch stars in Tucana with unprecedented precision, confirming dwarf spheroidals to be excellent laboratories to study the advanced evolution of low-mass stars.
3865. Tucana dSph galaxy spectroscopic dataset
ID:
ivo://CDS.VizieR/J/A+A/635/A152
Title:
Tucana dSph galaxy spectroscopic dataset
Short Name:
J/A+A/635/A152
Date:
21 Oct 2021
Publisher:
CDS
Description:
Isolated local group (LG) dwarf galaxies have evolved most or all of their life unaffected by interactions with the large LG spirals and therefore offer the opportunity to learn about the intrinsic characteristics of this class of objects. Our aim is to explore the internal kinematic and metallicity properties of one of the three isolated LG early-type dwarf galaxies, the Tucana dwarf spheroidal. This is an intriguing system, as it has been found in the literature to have an internal rotation of up to 16km/s, a much higher velocity dispersion than dwarf spheroidals of similar luminosity, and a possible exception to the too-big-too-fail problem. We present the results of a new spectroscopic dataset that we procured from the Very Large Telescope (VLT) taken with the FORS2 instrument in the region of the Ca II triplet for 50 candidate red giant branch stars in the direction of the Tucana dwarf spheroidal. These yielded line-of-sight (l.o.s.) velocity and metallicity ([Fe/H]) measurements of 39 effective members that double the number of Tucana's stars with such measurements. In addition, we re-reduce and include in our analysis the other two spectroscopic datasets presented in the literature, the VLT/FORS2 sample by Fraternali et al. (2009A&A...499..121F), and the VLT/FLAMES one from Gregory et al. (2019MNRAS.485.2010G). Across the various datasets analyzed, we consistently measure a l.o.s. systemic velocity of 180+/-1.3km/s and find that a dispersion-only model is moderately favored over models that also account for internal rotation. Our best estimate of the internal l.o.s. velocity dispersion is 6.2_-1.3_^+1.6^km/s, much smaller than the values reported in the literature and in line with similarly luminous dwarf spheroidals; this is consistent with NFW halos of circular velocities <30km/s. Therefore, Tucana does not appear to be an exception to the too-big-to-fail problem, nor does it appear to reside in a dark matter halo much more massive than those of its siblings. As for the metallicity properties, we do not find anything unusual; there are hints of the presence of a metallicity gradient, but more data are needed to pinpoint its presence.
3866. Tucana dwarf galaxy VI photometry
ID:
ivo://CDS.VizieR/J/A+A/310/715
Title:
Tucana dwarf galaxy VI photometry
Short Name:
J/A+A/310/715
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present deep CCD photometry for the dwarf galaxy in Tucana (l=323, b=-47.4). The data indicate that the galaxy is dominated by an intermediate/old stellar population with metallicity similar to that of the galactic globular clusters NGC 6752 and NGC 7089 (M2) (we find [Fe/H]=~-1.56). The distance modulus we derived, (m-M)_V_=~24.72+/-0.2, makes clear that this galaxy belongs to the Local Gro up. Tucana is clearly different from other dwarf galaxies, such as Leo I (Lee et al., 1993AJ....106.1420L), or Phoenix (Ortolani and Gratton, 1988PASP..100.1405O), because there is no evidence of a young stellar population (t<=5Gyrs) We suggest that the Tucana Galaxy is a genuine dwarf spheroidal in which no recent burst of star formation occurred.
3867. Tully-Fisher distances for Spitzer galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/444/527
Title:
Tully-Fisher distances for Spitzer galaxies
Short Name:
J/MNRAS/444/527
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper involves a data release of the observational campaign: Cosmicflows with Spitzer (CFS). Surface photometry of the 1270 galaxies constituting the survey is presented. An additional ~400 galaxies from various other Spitzer surveys are also analysed. CFS complements the Spitzer Survey of Stellar Structure in Galaxies, that provides photometry for an additional 2352 galaxies, by extending observations to low galactic latitudes (|b|<30{deg}). Among these galaxies are calibrators, selected in the K band, of the Tully-Fisher relation. The addition of new calibrators demonstrates the robustness of the previously released calibration. Our estimate of the Hubble constant using supernova host galaxies is unchanged, H_0_=75.2+/-3.3km/s/Mpc. Distance-derived radial peculiar velocities, for the 1935 galaxies with all the available parameters, will be incorporated into a new data release of the Cosmicflows project. The size of the previous catalogue will be increased by 20 percent, including spatial regions close to the Zone of Avoidance.
3868. Tully-Fisher relation at 0.1<z<1.0
ID:
ivo://CDS.VizieR/J/A+A/420/97
Title:
Tully-Fisher relation at 0.1<z<1.0
Short Name:
J/A+A/420/97
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using the Very Large Telescope in Multi Object Spectroscopy mode, we have observed a sample of 113 field spiral galaxies in the FORS Deep Field (FDF) with redshifts in the range 0.1<z<1.0. The galaxies were selected based on apparent brightness (R<23) and encompass all late spectrophotometric types from Sa to Sdm/Im. Spatially resolved rotation curves have been extracted for 77 galaxies and fitted with synthetic velocity fields taking into account all observational effects from inclination and slit misalignment to seeing and slit width. We also compared different shapes for the intrinsic rotation curve. To obtain robust values of Vmax, our analysis is focused on galaxies with rotation curves that extend well into the region of constant rotation velocity at large radii. If the slope of the local Tully-Fisher relation (TFR) is held fixed, we find evidence for a mass-dependent luminosity evolution which is as large as up to 2mag for the lowest-mass galaxies, but is small or even negligible for the highest-mass systems in our sample. In effect, the TFR slope is shallower at z~0.5 in comparison to the local sample. We argue for a mass-dependent evolution of the mass-to-light ratio. An additional population of blue, low-mass spirals does not seem a very appealing explanation. The flatter tilt we find for the distant TFR is in contradiction to the predictions of recent semi-analytic simulations.
3869. Tully-Fisher relation for SDSS galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/417/2347
Title:
Tully-Fisher relation for SDSS galaxies
Short Name:
J/MNRAS/417/2347
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper, we derive scaling relations between photometric observable quantities and disc galaxy rotation velocity V_rot_ or Tully-Fisher relations (TFRs). Our methodology is dictated by our purpose of obtaining purely photometric, minimal-scatter estimators of V_rot_ applicable to large galaxy samples from imaging surveys. To achieve this goal, we have constructed a sample of 189 disc galaxies at redshifts z<0.1 with long-slit H{alpha} spectroscopy from Pizagno et al. (2007, Cat. J/AJ/134/945) and new observations. By construction, this sample is a fair subsample of a large, well-defined parent disc sample of ~170000 galaxies selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7).
3870. Tully-Fisher relation for SDSS galaxies
ID:
ivo://CDS.VizieR/J/AJ/134/945
Title:
Tully-Fisher relation for SDSS galaxies
Short Name:
J/AJ/134/945
Date:
21 Oct 2021
Publisher:
CDS
Description:
We measure the relation between galaxy luminosity and disk circular velocity (the Tully-Fisher [TF] relation), in the g, r, i, and z bands, for a broadly selected sample of galaxies from the Sloan Digital Sky Survey, with the goal of providing well-defined observational constraints for theoretical models of galaxy formation. The input sample of 234 galaxies has a roughly flat distribution of absolute magnitudes in the range -18.5>M_r_>-22, and our only morphological selection is an isophotal axis ratio cut b/a<=0.6 to allow accurate inclination corrections. Long-slit spectroscopy from the Calar Alto and MDM observatories yields usable Halpha rotation curves for 162 galaxies (69%), with a representative color and morphology distribution. We define circular velocities V_80_ by evaluating the rotation curve at the radius containing 80% of the i-band light.

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