- ID:
- ivo://CDS.VizieR/J/AJ/127/660
- Title:
- Photometry in southern tail of the Antennae
- Short Name:
- J/AJ/127/660
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Hubble Space Telescope and Wide Field Planetary Camera 2 to image the putative tidal dwarf galaxy located at the tip of the Southern tidal tail of NGC 4038/4039, the Antennae. We resolve individual stars and identify two stellar populations. Hundreds of massive stars are present, concentrated into tight OB associations on scales of 200pc, with ages ranging from 2 to 100Myr. An older stellar population is distributed roughly following the outer contours of the neutral hydrogen in the tidal tail; we associate these stars with material ejected from the outer disks of the two spirals. The older stellar population has a red giant branch tip at I=26.5+/-0.2 from which we derive a distance modulus (m-M)_0_=30.7+/-0.25. The implied distance of 13.8+/-1.7Mpc is significantly smaller than commonly quoted distances for NGC 4038/4039. In contrast to the previously studied core of the merger, we find no superstar clusters (SSCs).
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- ID:
- ivo://CDS.VizieR/J/AJ/148/72
- Title:
- Photometry & interferometry of nearby secondaries
- Short Name:
- J/AJ/148/72
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To improve the statistics of hierarchical multiplicity, secondary components of wide nearby binaries with solar-type primaries were surveyed at the SOAR telescope for evaluating the frequency of subsystems. Images of 17 faint secondaries were obtained with the SOAR Adaptive Module that improved the seeing; one new 0.2'' binary was detected. For all targets, photometry in the g', i', z' bands is given. Another 46 secondaries were observed by speckle interferometry, resolving 7 close subsystems. Adding literature data, the binarity of 95 secondary components is evaluated. We found that the detection-corrected frequency of secondary subsystems with periods in the well-surveyed range from 10^3^ to 10^5^ days is 0.21+/-0.06--same as the normal frequency of such binaries among solar-type stars, 0.18. This indicates that wide binaries are unlikely to be produced by dynamical evolution of N-body systems, but are rather formed by fragmentation.
- ID:
- ivo://CDS.VizieR/J/ApJ/706/896
- Title:
- Photometry in the cometary globule Ori I-2
- Short Name:
- J/ApJ/706/896
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the young stellar population in and near the cometary globule Ori I-2. The analysis is based on deep Nordic Optical Telescope R-band and H{alpha} images, JCMT SCUBA 450 and 850um images combined with near-infrared Two Micron All Sky Survey (2MASS) photometry and mid-infrared archival Spitzer images obtained with the Infrared Array Camera (IRAC; 3.6, 4.5, 5.8, and 8um), and MIPS (24 and 70um) instruments. We identify a total of 125 sources within the 5'x5' region imaged by the IRAC. Of these sources, 87 are detected in the R-band image and 51 are detected in the 2MASS. Ori I-2 shows clear evidence of triggered star formation with four young low-luminosity pre-main-sequence (PMS) stars embedded in the globule. At least two, possibly as many as four, additional low-mass PMS objects were discovered in the field which are probably part of the young {sigma} Orionis cluster. Among the PMS stars which have formed in the globule, MIR-54 is a young, deeply embedded Class 0/I object; MIR-51 and 52 are young Class II sources, while MIR-89 is a more evolved, heavily extincted Class II object with its apparent colors mimicking a Class 0/I object. The Class 0/I object MIR-54 coincides with a previously known IRAS source and is a strong submillimeter source. It is most likely the source for the molecular outflow and the large parsec-scale Herbig-Haro (HH) flow. However, the nearby Class II source, MIR-52, which is strong a H{alpha} emission line star, also appears to drive an outflow approximately aligned with the outflow from MIR-54, and because of the proximity of the two outflows, either star could contribute. MIR-89 appears to excite a low-excitation HH object, HH 992, discovered for the first time in this study.
- ID:
- ivo://CDS.VizieR/J/AJ/64/28
- Title:
- Photometry in the globular cluster M22
- Short Name:
- J/AJ/64/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photovisual and photographic magnitudes of more than 400 stars in the globular cluster M22 have been measured. The resulting color-magnitude diagram extends to slightly fainter than the RR Lyurae domain and is generally similar to those for other globular clusters, in particular most resembling the diagram for M13
- ID:
- ivo://CDS.VizieR/J/ApJ/468/633
- Title:
- Photometry in the M31 OB association NGC 206
- Short Name:
- J/ApJ/468/633
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of our effort to determine what affects the star formation process by looking at the products of that process, we have obtained broadband Hubble Space Telescope images of the large OB association NGC 206 in the nearby spiral galaxy M31. Our images cover approximately the southern half of the association. We have detected stars down to an F555W magnitude of 25.5 and measure stars on the main sequence in NGC 206 to an M_F555W,0_ of -1 or a mass of ~6M_{sun}_. From a comparison with isochrones, ages up to about 8Myr are plausible, and we adopt an age of 6Myr. For stellar masses 6-15M_{sun}_, we determine an initial mass function slope of -1.4+/-0.5. This is close to the value for a Salpeter mass function, although the uncertainty is large. The uncertainty in the slope represents disagreement among the individual mass bins. In terms of intermediate-mass stars (6-15M_{sun}_) the NGC 206 star formation event appears to be typical of star formation processes in other nearby galaxies, and it is part of a growing number of studies ,that are finding similarities in the products of the star formation processes in a wide variety of star formation events and galactic environments. Nevertheless, the density of stars formed in NGC 206 is much lower than that in giant H II regions such as NGC 604 in M33 or 30 Doradus in the LMC and in typical OB associations.
- ID:
- ivo://CDS.VizieR/J/AJ/129/1832
- Title:
- Photometry in the NGC 4756 group of galaxies
- Short Name:
- J/AJ/129/1832
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is part of a series that focuses on investigating galaxy formation and evolution in small-scale systems of galaxies in low-density environments. We present results from a study of the NGC 4756 group, which is dominated by the elliptical galaxy NGC 4756. The characteristics of the group are investigated through (1) the detailed investigation of the morphological, photometric, and spectroscopic properties of nine galaxies among the dominant members of the group; (2) the determination of the photometric parameters of the faint galaxy population in an area of 34'x34' centered on NGC 4756; and (3) an analysis of the X-ray emission in the area based on archival data. The nine member galaxies are located in the core part of the NGC 4756 group (a strip~300kpc in diameter, H_0_=70km/s/Mpc), which has a very loose configuration. The central part of the NGC 4756 group contains a significant fraction of early-type galaxies.
- ID:
- ivo://CDS.VizieR/J/AJ/156/37
- Title:
- Photometry & Li abund. of cool dwarfs in M35
- Short Name:
- J/AJ/156/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Hydra spectra of 85 G-K dwarfs in the young cluster M35 near the Li 6708 {AA} line region are analyzed. From velocities and Gaia astrometry, 78 are likely single-star members that, combined with previous work, produce 108 members with T_eff_ ranging from 6150 to 4000 K as defined by multicolor, broadband photometry, E(B-V)=0.20, and [Fe/H]=-0.15, though there are indications the metallicity may be closer to solar. The Lithium abundance A(Li) follows a well-delineated decline from 3.15 for the hottest stars to upper limits =<1.0 among the coolest dwarfs. Contrary to earlier work, M35 includes single stars at systematically higher A(Li) than the mean cluster relation. This subset exhibits higher V_ROT_ than the more Li-depleted sample and, from photometric rotation periods, is dominated by stars classed as convective (C); all others are interface (I) stars. The cool, high-Li rapid rotators (RRs) are consistent with models that simultaneously consider rapid rotation and radius inflation; RRs hotter than the Sun exhibit excess Li depletion, as predicted by the models. The A(Li) distribution with color and rotation period, when compared to the Hyades/Praesepe and the Pleiades, is consistent with gyrochronological analysis placing M35's age between the older M34 and younger Pleiades. However, the Pleiades display a more excessive range in A(Li) and rotation period than M35 on the low-Li, slow-rotation side of the distribution, with supposedly younger stars at a given T_eff_ in the Pleiades spinning slower, with A(Li) reduced by more than a factor of four compared to M35.
- ID:
- ivo://CDS.VizieR/J/MNRAS/455/2918
- Title:
- Photometry & line luminosities for ASASSN-14li
- Short Name:
- J/MNRAS/455/2918
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based and Swift photometric and spectroscopic observations of the candidate tidal disruption event (TDE) ASASSN-14li, found at the centre of PGC 043234 (d~90 Mpc) by the All-Sky Automated Survey for SuperNovae (ASAS-SN). The source had a peak bolometric luminosity of L~10^44^ erg/s and a total integrated energy of E~7x10^50^ erg radiated over the ~6 months of observations presented. The UV/optical emission of the source is well fitted by a blackbody with roughly constant temperature of T~35000 K, while the luminosity declines by roughly a factor of 16 over this time. The optical/UV luminosity decline is broadly consistent with an exponential decline, L{prop.to}e^-t/t0^, with t_0_~60 d. ASASSN-14li also exhibits soft X-ray emission comparable in luminosity to the optical and UV emission but declining at a slower rate, and the X-ray emission now dominates. Spectra of the source show broad Balmer and helium lines in emission as well as strong blue continuum emission at all epochs. We use the discoveries of ASASSN-14li and ASASSN-14ae to estimate the TDE rate implied by ASAS-SN, finding an average rate of r~4.1x10^-5^/yr per galaxy with a 90 per cent confidence interval of (2.2-17.0)x10^-5^/yr per galaxy. ASAS-SN found roughly 1 TDE for every 70 Type Ia supernovae in 2014, a rate that is much higher than that of other surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/736/159
- Title:
- Photometry monitoring of the SN PTF10vdl
- Short Name:
- J/ApJ/736/159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Palomar Transient Factory (PTF) is an optical wide-field variability survey carried out using a camera with a 7.8deg^2^ field of view mounted on the 48 inch Oschin Schmidt telescope at Palomar Observatory. One of the key goals of this survey is to conduct high-cadence monitoring of the sky in order to detect optical transient sources shortly after they occur. Here, we describe the real-time capabilities of the PTF and our related rapid multiwavelength follow-up programs, extending from the radio to the {gamma}-ray bands. We present as a case study observations of the optical transient PTF10vdl (SN 2010id), revealed to be a very young core-collapse (Type II-P) supernova having a remarkably low luminosity. Our results demonstrate that the PTF now provides for optical transients the real-time discovery and rapid-response follow-up capabilities previously reserved only for high-energy transients like gamma-ray bursts.
- ID:
- ivo://CDS.VizieR/J/A+AS/118/7
- Title:
- Photometry & morphology of UCM galaxies
- Short Name:
- J/A+AS/118/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of Thuan & Gunn r CCD imaging observations of the Universidad Complutense de Madrid (UCM) sample of emission-line galaxies (ELGs), selected by the presence of H{alpha} emission in low-resolution objective prism spectra. In this work we characterize photometrically and morphologically a total of 212 objects from the UCM survey. This Paper presents the observations and basic reductions, and lists a set of photometric parameters calculated for each UCM object. In addition, for the first time in a ELGs sample, we have determined the morphological classification of the objects using simultaneously five different criteria.