- ID:
- ivo://CDS.VizieR/J/A+A/455/107
- Title:
- 3D spectroscopy with VLT/GIRAFFE
- Short Name:
- J/A+A/455/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A precise derivation of the evolution of the Tully-Fisher is crucial to understand the interplay between dark matter and baryonic matter in cosmological models, using 15 deployable integral field units of FLAMES/GIRAFFE at VLT, we have recovered the velocity fields of 35 galaxies at intermediate redshift (0.4<z<0.75). This facility is able to recover the velocity fields of almost all the emission line galaxies with I_AB_<=22.5 and W_0_(OII)>=15{AA}. In our sample, we find only 35% rotating disks. These rotating disks produce a Tully-Fisher relationship (stellar mass or MK versus Vmax which has apparently not evolved in slope, zero point and scatter since z=0.6). The only evolution found is a brightening of the B band luminosity of a third of the disks, possibly due to an enhancement of the star formation. The very large scatters found in previously reported Tully-Fisher relationships at moderate redshifts are caused by the numerous (65%) galaxies with perturbed or complex kinematics. Those galaxies include minor or major mergers, merger remnants and/or inflow/outflows and their kinematics can be easily misidentified by slit spectroscopy. Their presence suggests a strong evolution in the dynamical properties of galaxies during the last 7Gyr.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/779/7
- Title:
- dSph satellites of M31. I. Variables in And XIX
- Short Name:
- J/ApJ/779/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present B, V time-series photometry of Andromeda XIX (And XIX), the most extended (half-light radius of 6.2') of Andromeda's dwarf spheroidal companions, which we observed with the Large Binocular Cameras at the Large Binocular Telescope. We surveyed a 23'x23' area centered on And XIX and present the deepest color-magnitude diagram (CMD) ever obtained for this galaxy, reaching, at V~26.3mag, about one magnitude below the horizontal branch (HB). The CMD shows a prominent and slightly widened red giant branch, along with a predominantly red HB, which extends to the blue to significantly populate the classical instability strip. We have identified 39 pulsating variable stars, of which 31 are of RR Lyrae type and 8 are Anomalous Cepheids (ACs). Twelve of the RR Lyrae variables and three of the ACs are located within And XIX's half light radius. The average period of the fundamental mode RR Lyrae stars (<P_ab_>{=}0.62days, {sigma}=0.03days) and the period-amplitude diagram qualify And XIX as an Oosterhoff-Intermediate system. From the average luminosity of the RR Lyrae stars (<V(RR)>=25.34mag, {sigma}=0.10mag), we determine a distance modulus of (m-M)_0_=24.52+/-0.23mag in a scale where the distance to the Large Magellanic Cloud (LMC) is 18.5+/-0.1mag. The ACs follow a well-defined Period-Wesenheit (PW) relation that appears to be in very good agreement with the PW relationship defined by the ACs in the LMC.
- ID:
- ivo://CDS.VizieR/J/AJ/150/151
- Title:
- DSSI observations of binaries. VI. Measures in 2014
- Short Name:
- J/AJ/150/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of 938 speckle measures of double stars and suspected double stars drawn mainly from the Hipparcos Catalog, as well as 208 observations where no companion was noted. One hundred fourteen pairs have been resolved for the first time. The data were obtained during four observing runs in 2014 using the Differential Speckle Survey Instrument at Lowell Observatory's Discovery Channel Telescope. The measurement precision obtained when comparing to ephemeris positions of binaries with very well-known orbits is generally less than 2mas in separation and 0.5{deg} in position angle. Differential photometry is found to have internal precision of approximately 0.1mag and to be in very good agreement with Hipparcos measures in cases where the comparison is most relevant. We also estimate the detection limit in the cases where no companion was found. Visual orbital elements are derived for six systems.
- ID:
- ivo://CDS.VizieR/J/AJ/157/56
- Title:
- DSSI observations of binary & trinary star systems
- Short Name:
- J/AJ/157/56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 248 speckle observations of 43 binary and 19 trinary star systems chosen to make progress in two main areas of investigation: the fundamental properties of metal-poor stars and star formation mechanisms. The observations were taken at the Gemini North and South telescopes during the period 2015 July to 2018 April, mainly with the Differential Speckle Survey Instrument but also with a few early results from the new 'Alopeke speckle camera at Gemini North. We find that the astrometry and photometry of these observations as a whole are consistent with previous work at Gemini. We present five new visual orbits for systems important in understanding metal-poor stars, three of which have orbital periods of less than 4 yr, and we indicate the degree to which these and future observations can impact our knowledge of stellar properties and star formation. In particular, we find a decrease in mass at fixed spectral type for metal-poor stars versus their solar-metallicity analogs that is consistent with predictions that are made from current stellar models.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A11
- Title:
- DUNES survey observational results
- Short Name:
- J/A+A/555/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems. Their solar system's counterparts are the asteroid and Edgeworth-Kuiper belts. The Herschel Open Time Key Programme DUNES (DUst around NEarby Stars) survey aims at detecting extra-solar analogues to the Edgeworth-Kuiper belt around solar-type stars, putting in this way the solar system into context. We used Herschel/PACS to observe a sample of nearby FGK stars. Data at 100 and 160 micron were obtained, complemented in some cases with observations at 70 micron, and at 250, 350 and 500 micron using SPIRE. The paper provides a detailed description of the observational results of the survey.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A109
- Title:
- Dust and PAH emission SEDs of disk galaxies
- Short Name:
- J/A+A/527/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a self-consistent model of the spectral energy distributions (SEDs) of spiral galaxies from the ultraviolet (UV) to the mid-infrared (MIR)/far-infrared (FIR)/submillimeter (submm) based on a full radiative transfer calculation of the propagation of starlight in galaxy disks. This model predicts not only the total integrated energy absorbed in the UV/optical and re-emitted in the infrared/submm, but also the colours of the dust emission based on an explicit calculation of the strength and colour of the UV/optical radiation fields heating the dust, and incorporating a full calculation of the stochastic heating of small dust grains and PAH molecules. The geometry of the translucent components of the model is empirically constrained using the results from the radiation transfer analysis of Xilouris et al. on spirals in the middle range of the Hubble sequence, while the geometry of the optically thick components is constrained from physical considerations with a posteriori checks of the model predictions with observational data. These geometrical constraints enable the dust emission to be predicted in terms of a minimum set of free parameters: the central face-on dust opacity in the B-band {tau}^f^_B_, a clumpiness factor F for the star-forming regions, the star-formation rate SFR, the normalised luminosity of the old stellar population old and the bulge-to-disk ratio B/D. The results of the calculations are made available in the form of a large library of simulated dust emission SEDs spanning the whole parameter space of our model, together with the corresponding library of dust attenuation calculated using the same model.
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/1412
- Title:
- Dust and SSP-stellar parameters of M82
- Short Name:
- J/MNRAS/452/1412
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use near ultraviolet and optical photometry to investigate the dust properties in the nearby starburst galaxy M82. By combining imaging from the Swift/UVOT instrument and optical data from the Sloan Digital Sky Survey, we derive the extinction curve parametrized by the standard R_V_ factor, and the strength of the NUV 2175 {AA} feature - quantified by a parameter B - out to projected galactocentric distances of 4 kpc. Our analysis is robust against possible degeneracies from the properties of the underlying stellar populations. Both B and R_V_ correlate with galactocentric distance, revealing a systematic trend of the dust properties. Our results confirm previous findings that dust in M82 is better fitted by a Milky Way standard extinction curve, in contrast to a Calzetti law. We find a strong correlation between R_V_ and B, towards a stronger NUV bump in regions with higher R_V_, possibly reflecting a distribution with larger dust grain sizes. The data we use were taken before SN2014J, and therefore can be used to probe the properties of the interstellar medium before the event. Our R_V_ values around the position of the supernova are significantly higher than recent measurements post-SN2014J (R_V_~1.4). This result is consistent with a significant change in the dust properties after the supernova event, either from disruption of large grains or from the contribution by an intrinsic circumstellar component. Intrinsic variations among supernovae not accounted for could also give rise to this mismatch.
- ID:
- ivo://CDS.VizieR/J/A+A/553/A80
- Title:
- Dust effects on photometric parameters in spirals
- Short Name:
- J/A+A/553/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a study made to quantify the effects of dust on the derived photometric parameters of disks (old and young stellar disks) and bulges: disk scale-lengths, axis-ratios, central surface-brightness, bulge effective radii, and Sersic indices. The changes in the derived photometric parameters from their intrinsic values (as would be seen in the absence of dust) were obtained by fitting simulated images of disks and bulges produced using radiative transfer calculations. The simulations were fitted with the GALFIT 3.0.2 data analysis algorithm and the fitted models were the commonly used infinitely thin disks described by exponential, general Sersic and de Vaucouleurs distributions.
- ID:
- ivo://CDS.VizieR/J/A+A/557/A137
- Title:
- Dust effects on photometric parameters in spirals
- Short Name:
- J/A+A/557/A137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a study to quantify the effects of dust on the derived photometric parameters of disk and bulges obtained from bulge-disk decomposition: scale-length, effective radius, Sersic index, disk axis-ratio, and bulge-to-disk ratio. The dust induced changes in these parameters were obtained by fitting simulated images of composite systems (containing a disk and a bulge) produced using radiative transfer calculations. The simulations were fitted with the GALFIT 3.0.2 data analysis algorithm. Fits were done with both a combination of an exponential plus a variable- index Sersic function as well as with a combination of two variable-index Sersic functions.
- ID:
- ivo://CDS.VizieR/J/A+A/622/A132
- Title:
- Dust emission profiles of DustPedia galaxies
- Short Name:
- J/A+A/622/A132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most radiative transfer models assume that dust in spiral galaxies is distributed exponentially. In this paper our goal is to verify this assumption by analysing the two-dimensional large-scale distribution of dust in galaxies from the DustPedia sample. For this purpose, we have made use of Herschel imaging in five bands, from 100 to 500um, in which the cold dust constituent is primarily traced and makes up the bulk of the dust mass in spiral galaxies. For a subsample of 320 disc galaxies, we successfully performed a simultaneous fitting with a single Sersic model of the Herschel images in all five bands using the multi-band modelling code GALFITM. We report that the Sersic index n, which characterises the shape of the Sersic profile, lies systematically below 1 in all Herschel bands and is almost constant with wavelength. The average value at 250um is 0.67+/-0.37 (187 galaxies are fitted with n^250^<=0.75, 87 galaxies have 0.75<n^250^<=1.25, and 46 - with n^250^>1.25). Most observed profiles exhibit a depletion in the inner region (at r<0.3-0.4 of the optical radius r25) and are more or less exponential in the outer part. We also find breaks in the dust emission profiles at longer distances (0.5-0.6)r25 which are associated with the breaks in the optical and near-infrared. We assumed that the observed deficit of dust emission in the inner galaxy region is related to the depression in the radial profile of the HI surface density in the same region because the atomic gas reaches high enough surface densities there to be transformed into molecular gas. If a galaxy has a triggered star formation in the inner region (for example, because of a strong bar instability, which transfers the gas inwards to the centre, or a pseudobulge formation), no depletion or even an excess of dust emission in the centre is observed.
