- ID:
- ivo://CDS.VizieR/J/ApJ/649/862
- Title:
- IR phot. of IC 348 pre-main-sequence stars
- Short Name:
- J/ApJ/649/862
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 105 stellar rotation periods in the young cluster IC 348, 75 of which are new detections, increasing the total number of known periods in this cluster to 143. The period distribution resembles that seen in the heart of the Orion Nebula cluster by Herbst and colleagues. Stars estimated to be less massive than 0.25M_{sun}_ show a unimodal distribution of fast rotators (P~1-2days) and a tail of slower rotators, while stars estimated to be more massive than 0.25M_{sun}_ show a bimodal distribution with peaks at 2 and 8-days. We combine all published rotation periods in IC 348 with Spitzer mid-IR (3.6, 4.5, 5.8, and 8.0um) photometry, an unprecedentedly efficient and reliable disk indicator, in order to test the disk-braking paradigm.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/471/813
- Title:
- IR photometry around IRAS 16571-4029
- Short Name:
- J/A+A/471/813
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a near-infrared survey of the young stellar cluster associated with the IRAS 16571-4029 source. The main purpose of this survey is to study the cluster members and find the ionizing sources of the associated HII region.
- ID:
- ivo://CDS.VizieR/J/ApJ/758/31
- Title:
- IR photometry for members of Upper Sco
- Short Name:
- J/ApJ/758/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry at 3-24{mu}m for all known members of the Upper Scorpius association ({tau}~11Myr) based on all images of these objects obtained with the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer. We have used these data to identify the members that exhibit excess emission from circumstellar disks and estimate the evolutionary stages of these disks. Through this analysis, we have found ~50 new candidates for transitional, evolved, and debris disks. The fraction of members harboring inner primordial disks is <~10% for B-G stars (M>1.2M_{sun}_) and increases with later types to a value of ~25% at >~M5 (M<~0.2 M_{sun}_), in agreement with the results of previous disk surveys of smaller samples of Upper Sco members. These data indicate that the lifetimes of disks are longer at lower stellar masses and that a significant fraction of disks of low-mass stars survive for at least ~10Myr. Finally, we demonstrate that the distribution of excess sizes in Upper Sco and the much younger Taurus star-forming region ({tau}~1Myr) is consistent with the same, brief timescale for clearing of inner disks.
- ID:
- ivo://CDS.VizieR/J/ApJ/722/1226
- Title:
- IR photometry in {lambda} Orionis cluster
- Short Name:
- J/ApJ/722/1226
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present IRAC/MIPS Spitzer Space Telescope observations of the solar-type and the low-mass stellar population of the young (~5Myr) {lambda} Orionis cluster. Combining optical and Two Micron All Sky Survey photometry, we identify 436 stars as probable members of the cluster. Given the distance (450pc) and the age of the cluster, our sample ranges in mass from 2M_{sun}_ to objects below the substellar limit. With the addition of the Spitzer mid-infrared data, we have identified 49 stars bearing disks in the stellar cluster. Using spectral energy distribution slopes, we place objects in several classes: non-excess stars (diskless), stars with optically thick disks, stars with "evolved disks" (with smaller excesses than optically thick disk systems), and "transitional disk" candidates (in which the inner disk is partially or fully cleared). The disk fraction depends on the stellar mass, ranging from ~6% for K-type stars (R_C_-J<2) to ~27% for stars with spectral-type M5 or later (R_C_-J>4). We confirm the dependence of disk fraction on stellar mass in this age range found in other studies. Regarding clustering levels, the overall fraction of disks in the {lambda} Orionis cluster is similar to those reported in other stellar groups with ages normally quoted as ~5Myr.
- ID:
- ivo://CDS.VizieR/J/ApJ/686/1195
- Title:
- IR photometry in the {gamma} Vel cluster
- Short Name:
- J/ApJ/686/1195
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new Spitzer Space Telescope observations of stars in the young (~5Myr) {gamma} Velorum stellar cluster. Combining optical and 2MASS photometry, we have selected 579 stars as candidate members of the cluster. With the addition of the Spitzer mid-infrared data, we have identified five debris disks around A-type stars and five to six debris disks around solar-type stars, indicating that the strong radiation field in the cluster does not completely suppress the production of planetesimals in the disks of cluster members. However, we find some evidence that the frequency of circumstellar primordial disks is lower, and the infrared flux excesses are smaller than for disks around stellar populations with similar ages.
- ID:
- ivo://CDS.VizieR/J/ApJ/638/897
- Title:
- IR photometry in Trumpler 37 and NGC 7160
- Short Name:
- J/ApJ/638/897
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an infrared imaging survey of two clusters in the Cep OB2 Association, Tr 37 and NGC 7160, using the IRAC and MIPS instruments on board the Spitzer Space Telescope. Our observations cover the wavelength range from 3.6 to 24{mu}m, allowing us to detect disk emission over a typical range of radii ~0.1 to ~20AU from the central star.
- ID:
- ivo://CDS.VizieR/J/A+A/608/A66
- Title:
- IR photometry in UKIDSS sigma Orionis stars
- Short Name:
- J/A+A/608/A66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We search for new planetary mass objects by combining our deep I-band photometry with public J-band magnitudes and by examining the nearby environment of known very low mass members for possible companions. Our analysis confirms the existing census of substellar cluster members down to approximately 7M_Jup_.
- ID:
- ivo://CDS.VizieR/J/ApJ/835/74
- Title:
- IR photometry of AGNs in Swift/BAT 70 month cat.
- Short Name:
- J/ApJ/835/74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We systematically investigate the near- to far-infrared (FIR) photometric properties of a nearly complete sample of local active galactic nuclei (AGNs) detected in the Swift/Burst Alert Telescope (BAT) all-sky ultra-hard X-ray (14-195keV) survey. Out of 606 non-blazar AGNs in the Swift/BAT 70 month catalog at high galactic latitudes of |b|>10{deg}, we obtain IR photometric data of 604 objects by cross-matching the AGN positions with catalogs from the WISE, AKARI, IRAS, and Herschel infrared observatories. We find a good correlation between the ultra-hard X-ray and mid-IR luminosities over five orders of magnitude (41<logL_14-195_<46). Informed by previous measurements of the intrinsic spectral energy distribution of AGNs, we find FIR pure-AGN candidates whose FIR emission is thought to be AGN-dominated with low star-formation activity. We demonstrate that the dust covering factor decreases with the bolometric AGN luminosity, confirming the luminosity-dependent unified scheme. We also show that the completeness of the WISE color-color cut in selecting Swift/BAT AGNs increases strongly with 14-195keV luminosity.
- ID:
- ivo://CDS.VizieR/J/A+A/436/853
- Title:
- IR photometry of Alpha Per low-mass members
- Short Name:
- J/A+A/436/853
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a near-infrared (K'-band) survey of 0.7 square degree area in the {alpha} Persei open cluster (age=90Myr, distance=182pc) carried out with the Omega-Prime camera on the Calar Alto 3.5-m telescope. Combining optical data (Rc and Ic) obtained with the KPNO/MOSA detector and presented in Stauffer et al. (1999ApJ...527..219S; S99) with the K' observations, a sample of new candidate members has been extracted from the optical-infrared colour-magnitude diagram. The location of these candidates in the colour-colour diagram suggests that two-thirds of them are actually reddened background giants. About 20 new candidate members with masses between 0.3 and 0.04M_{sun}_ are added to the ~400 known Alpha Per cluster members. If they are indeed Alpha Per members, four of the new candidates would be brown dwarfs. We discuss the advantages and drawbacks of the near-infrared survey as compared to the optical selection method. We also describe the outcome of optical spectroscopy obtained with the Twin spectrograph on the Calar Alto 3.5-m telescope for about 30 candidates, including selected members from the optical sample presented in Barrado y Navascues et al. (2002, Cat. <J/A+A/395/813>) and from our joint optical/infrared catalogue. These results argue in favour of the optical selection method for this particular cluster.
- ID:
- ivo://CDS.VizieR/J/ApJ/642/972
- Title:
- IR photometry of a star-forming core in NGC 2264
- Short Name:
- J/ApJ/642/972
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze Spitzer and Magellan observations of a star-forming core near IRS 2 in the young cluster NGC 2264. The submillimeter source IRAS 12 S1, previously believed to be an intermediate-mass Class 0 object is shown to be a dense collection of embedded, low-mass stars. We argue that this group of stars represents the fragmenting collapse of a dense, turbulent core, using a number of indicators of extreme youth. With reasonable estimates for the velocity dispersion in the group, we estimate a dynamical lifetime of only a few times 10^4^yr. Spectral energy distributions of stars in the core are consistent with Class I or Class 0 assignments. We present observations of an extensive system of molecular hydrogen emission knots. The luminosity of the objects in the core region are consistent with roughly solar mass protostars.
