- ID:
- ivo://CDS.VizieR/J/AJ/159/153
- Title:
- Optical and IR photometry in the HII region Sh2-242
- Short Name:
- J/AJ/159/153
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present here identification and characterization of the young stellar population associated with an active star-forming site Sh2-242. We used our own new optical imaging and spectroscopic observational data, as well as several archival catalogs, e.g., Pan-STARRS-1, Gaia-DR2, Isaac Newton Telescope Photometric H-Alpha Survey (IPHAS), Wide-field InfraRed Camera, 2MASS, and Spitzer. Slit spectroscopic results confirm the classification of the main ionizing source BD+26980 as an early-type star of spectral type B0.5V. The spectrophotometric distance of the star is estimated as 2.08{+/-}0.24kpc, which confirms the source as a member of the cluster. An extinction map covering a large area (diameter ~50') is generated with H and K photometry toward the region. From the map, three distinct locations of peak extinction complexes (A_V_~7-17mag) are identified for the very first time. Using the infrared color excess, a total of 33 Class I and 137 Class II young objects are classified within the region. The IPHAS photometry reveals classification of 36 H{alpha} emitting sources, which might be class II objects. Among 36 H{alpha} emitting sources, 5 are already identified using infrared excess emission. In total, 201 young objects are classified toward S242 from this study. The membership status of the young sources is further windowed with the inclusion of parallax from the Gaia DR2 catalog. Using the optical and infrared color-magnitude diagrams, the young stellar objects are characterized with an average age of ~1Myr and masses in the range 0.1-3.0M_{sun}_.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/213/19
- Title:
- Optical and near-IR light curves of 64 SNe
- Short Name:
- J/ApJS/213/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a densely sampled, homogeneous set of light curves of 64 low-redshift (z<~0.05) stripped-envelope supernovae (SNe of Type IIb, Ib, Ic, and Ic-BL). These data were obtained between 2001 and 2009 at the Fred L. Whipple Observatory (FLWO) on Mount Hopkins in Arizona, with the optical FLWO 1.2m and the near-infrared (NIR) Peters Automated Infrared 1.3m telescopes. Our data set consists of 4543 optical photometric measurements on 61 SNe, including a combination of UBVRI, UBVr'i', and u'BVr'i', and 1919 JHK_s_ NIR measurements on 25 SNe. This sample constitutes the most extensive multi-color data set of stripped-envelope SNe to date. Our photometry is based on template-subtracted images to eliminate any potential host-galaxy light contamination. This work presents these photometric data, compares them with data in the literature, and estimates basic statistical quantities: date of maximum, color, and photometric properties. We identify promising color trends that may permit the identification of stripped-envelope SN subtypes from their photometry alone. Many of these SNe were observed spectroscopically by the Harvard-Smithsonian Center for Astrophysics (CfA) SN group, and the spectra are presented in a companion paper. A thorough exploration that combines the CfA photometry and spectroscopy of stripped-envelope core-collapse SNe will be presented in a follow-up paper.
- ID:
- ivo://CDS.VizieR/J/ApJ/895/118
- Title:
- Optical and NIR photometry of 2 Ia type supernovae
- Short Name:
- J/ApJ/895/118
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- We present photometric and spectroscopic observations of SN2013aa and SN2017cbv, two nearly identical type Ia supernovae (SNeIa) in the host galaxy NGC5643. The optical photometry has been obtained using the same telescope and instruments used by the Carnegie Supernova Project. This eliminates most instrumental systematics and provides light curves in a stable and well-understood photometric system. Having the same host galaxy also eliminates systematics due to distance and peculiar velocity, providing an opportunity to directly test the relative precision of SNeIa as standard candles. The two SNe have nearly identical decline rates, negligible reddenings, and remarkably similar spectra, and, at a distance of ~20Mpc, they are ideal potential calibrators for the absolute distance using primary indicators such as Cepheid variables. We discuss to what extent these two SNe can be considered twins and compare them with other supernova "siblings" in the literature and their likely progenitor scenarios. Using 12 galaxies that hosted two or more SNe Ia, we find that when using SNeIa, and after accounting for all sources of observational error, one gets consistency in distance to 3%.
- ID:
- ivo://CDS.VizieR/J/ApJS/190/166
- Title:
- Optical catalog of AKARI NEP-wide survey
- Short Name:
- J/ApJS/190/166
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the source catalog and the properties of the B-, R-, and I-band images obtained to support the AKARI North Ecliptic Pole Wide (NEP-Wide) survey. The NEP-Wide is an AKARI infrared imaging survey of the north ecliptic pole covering a 5.8deg^2^ area over 2.5-6um wavelengths. The optical imaging data were obtained at the Maidanak Observatory in Uzbekistan using the Seoul National University 4kx4k Camera on the 1.5m telescope. These images cover 4.9deg^2^ where no deep optical imaging data are available. Our B-, R-, and I-band data reach the depths of ~23.4, ~23.1, and ~22.3mag(AB) at 5{sigma}, respectively. The source catalog contains 96460 objects in the R band, and the astrometric accuracy is about 0.15" at 1{sigma} in each RA and DEC direction. These photometric data will be useful for many studies including identification of optical counterparts of the infrared sources detected by AKARI, analysis of their spectral energy distributions from optical through infrared, and the selection of interesting objects to understand the obscured galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/MNRAS/238/1171
- Title:
- Optical/IR observ. of Radio Galaxies and QSOs
- Short Name:
- J/MNRAS/238/1171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog reports on an extensive optical and infrared study of the 178 radio sources in the Parkes Selected Regions (S > 100 mJy at 2.7 GHz). CCD observations have resulted in the essential completion (95 percent) of optical identifications and have provided B and R photometry. In addition, K photometry has been completed for four of the six selected regions.
- ID:
- ivo://CDS.VizieR/J/A+A/530/A90
- Title:
- Optically bright post-AGB population of LMC
- Short Name:
- J/A+A/530/A90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We construct a catalogue of the optically bright post-AGB stars in the LMC. The sample forms an ideal testbed for stellar evolution theory predictions of the final phase of low- and intermediate-mass stars, because the distance and hence luminosity and also the current and initial mass of these objects is well constrained.
- ID:
- ivo://CDS.VizieR/J/ApJ/769/108
- Title:
- Optical photometry of 4 millisecond pulsars
- Short Name:
- J/ApJ/769/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the last few years, over 43 millisecond radio pulsars have been discovered by targeted searches of unidentified {gamma}-ray sources found by the Fermi Gamma-Ray Space Telescope. A large fraction of these millisecond pulsars are in compact binaries with low-mass companions. These systems often show eclipses of the pulsar signal and are commonly known as black widows and redbacks because the pulsar is gradually destroying its companion. In this paper, we report on the optical discovery of four strongly irradiated millisecond pulsar companions. All four sources show modulations of their color and luminosity at the known orbital periods from radio timing. Light curve modeling of our exploratory data shows that the equilibrium temperature reached on the companion's dayside with respect to their nightside is consistent with about 10%-30% of the available spin-down energy from the pulsar being reprocessed to increase the companion's dayside temperature. This value compares well with the range observed in other irradiated pulsar binaries and offers insights about the energetics of the pulsar wind and the production of {gamma}-ray emission. In addition, this provides a simple way of estimating the brightness of irradiated pulsar companions given the pulsar spin-down luminosity. Our analysis also suggests that two of the four new irradiated pulsar companions are only partially filling their Roche lobe. Some of these sources are relatively bright and represent good targets for spectroscopic follow-up.
- ID:
- ivo://CDS.VizieR/J/ApJS/183/261
- Title:
- Optical photometry of the ONC
- Short Name:
- J/ApJS/183/261
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present U, B, V, I broadband, 6200{AA} TiO medium band, and H{alpha} narrow band photometry of the Orion Nebula Cluster (ONC) obtained with the WFI imager at the ESO/MPI 2.2 telescope at La Silla Observatory. The nearly simultaneous observations cover the entire ONC in a field of about 34x34arcmin^2^. They enable us to determine stellar colors avoiding the additional scatter in the photometry induced by stellar variability typical of pre-main-sequence stars. We identify 2612 point-like sources in the I band; 58%, 43%, and 17% of them are also detected in V, B, and U, respectively. 1040 sources are identified in the H{alpha} band. In this paper we present the observations, the calibration techniques adopted, and the resulting catalog. We show the derived color-magnitude diagram of the population and discuss the completeness of our photometry. We define a spectrophotometric TiO index that takes into account the fluxes in the V, I, and TiO bands. Comparing it with spectral types of ONC members in the literature, we find a correlation between the index and the spectral type valid for M-type stars, which is accurate to better than 1 spectral subclass for M3-M6 types and better than 2 spectral subclasses for M0-M2 types. This allows us to newly classify 217 stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/806/94
- Title:
- Optical polarimetric catalog of stars in the SMC
- Short Name:
- J/ApJ/806/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new optical polarimetric catalog for the Small Magellanic Cloud (SMC). It contains a total of 7207 stars, located in the northeast (NE) and Wing sections of the SMC and part of the Magellanic Bridge. This new catalog is a significant improvement compared to previous polarimetric catalogs for the SMC. We used it to study the sky-projected interstellar magnetic field structure of the SMC. Three trends were observed for the ordered magnetic field direction at position angles (PAs) of (65{deg}+/-10{deg}), (115{deg}+/-10{deg}), and (150{deg}+/-10{deg}). Our results suggest the existence of an ordered magnetic field aligned with the Magellanic Bridge direction and SMC's Bar in the NE region, which have PAs roughly at 115.4{deg} and 45{deg}, respectively. However, the overall magnetic field structure is fairly complex. The trends at 115{deg} and 150{deg} may be correlated with the SMC's bimodal structure, observed in Cepheids' distances and HI velocities. We derived a value of B_sky_=(0.497+/-0.079){mu}G for the ordered sky-projected magnetic field, and {delta}B=(1.465+/-0.069){mu}G for the turbulent magnetic field. This estimate of B_sky_ is significantly larger (by a factor of ~10) than the line of sight field derived from Faraday rotation observations, suggesting that most of the ordered field component is on the plane of the sky. A turbulent magnetic field stronger than the ordered field agrees with observed estimates for other irregular and spiral galaxies. For the SMC the B_sky_/{delta}B ratio is closer to what is observed for our Galaxy than other irregular dwarf galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJS/230/3
- Title:
- Optical & Spitzer photometry in IC 1805
- Short Name:
- J/ApJS/230/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep wide-field optical CCD photometry and mid-infrared Spitzer/IRAC and MIPS 24{mu}m data for about 100000 stars in the young open cluster IC 1805. The members of IC 1805 were selected from their location in the various color-color and color-magnitude diagrams, and the presence of H{alpha} emission, mid-infrared excess emission, and X-ray emission. The reddening law toward IC 1805 is nearly normal (R_V_=3.05+/-0.06). However, the distance modulus of the cluster is estimated to be 11.9+/-0.2mag (d=2.4+/-0.2kpc) from the reddening-free color-magnitude diagrams, which is larger than the distance to the nearby massive star-forming region W3(OH) measured from the radio VLBA astrometry. We also determined the age of IC 1805 ({tau}_MSTO_=3.5Myr). In addition, we critically compared the age and mass scale from two pre-main-sequence evolution models. The initial mass function with a Salpeter-type slope of {Gamma}=-1.3+/-0.2 was obtained and the total mass of IC 1805 was estimated to be about 2700+/-200M_{sun}_. Finally, we found our distance determination to be statistically consistent with the Tycho-Gaia Astrometric Solution Data Release 1, within the errors. The proper motion of the B-type stars shows an elongated distribution along the Galactic plane, which could be explained by some of the B-type stars being formed in small clouds dispersed by previous episodes of star formation or supernova explosions.
