We have determined the ratios of total to selective extinction in the near-infrared bands (J; H; K s ) toward the Galactic center from the observations of the region jlj P 2N0 and 0N5 PjbjP1N0 with the IRSF telescope and the SIRIUS camera. Using the positions of red clump stars in color-magnitude diagrams as a tracer of the extinction and reddening, we determine the average of the ratios of total to selective extinction to be A K s /E HÀK s ¼ 1:44 AE 0:01, A K s /E J ÀK s ¼ 0:494 AE 0:006, and A H /E J ÀH ¼ 1:42 AE 0:02, which are significantly smaller than those obtained in previous studies. From these ratios, we estimate that A J :A H : A K s ¼ 1:0:573 AE 0:009:0:331 AE 0:004 and E J ÀH /E HÀK s ¼ 1:72 AE 0:04, and we find that the power law A k / k À1:99AE0:02 is a good approximation over these wavelengths. Moreover, we find a small variation in A K s /E HÀK s across our survey. This suggests that the infrared extinction law changes from one line of sight to another, and the so-called universality does not necessarily hold in the infrared wavelengths.

We present high-resolution, H-band, imaging observations, collected with Subaru/HiCIAO, of the scattered light from the transitional disk around SAO 206462 (HD 135344B). Although previous submm imagery suggested the existence of the dust-depleted cavity at r ≤ 46 AU, our observations reveal the presence of scattered light components as close as 0. ′′ 2 (∼ 28 AU) from the star. Moreover, we have discovered two small-scale spiral structures lying within 0. ′′ 5 (∼ 70 AU). We present models for the spiral structures using the spiral density wave theory, and derive a disk aspect ratio of h ∼ 0.1, which is consistent with previous sub-mm observations. This model can potentially give estimates of the temperature and rotation profiles of the disk based on dynamical processes, independently from sub-mm observations. It also predicts the evolution of the spiral structures, which can be observable on timescales of 10-20 years, providing conclusive tests of the model. While we cannot uniquely identify the origin of these spirals, planets embedded in the disk may be capable of exciting the observed morphology. Assuming that this is the case, we can make predictions on the locations and, possibly, the masses of the unseen planets. Such planets may be detected by future multi-wavelengths observations.

We present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets and Disks with Subaru, and 1.1µm HST/NICMOS data. While sub-millimeter studies suggested there is a dustdepleted cavity with r=0. ′′ 35, we find scattered light as close as 0.1 ′′ (20-28 AU) from the star, with no visible cavity at H, K', or K s . We find two small-scaled spiral structures which asymmetrically shadow the outer disk. We model one of the spirals using spiral density wave theory, and derive a disk aspect ratio of h∼0.18, indicating a dynamically warm disk. If the spiral pattern is excited by a perturber, we estimate its mass to be 5 +3 −4 M J , in the range where planet filtration models predict accretion continuing onto the star. Using a combination of non-redundant aperture masking data at L ′ and angular differential imaging with Locally Optimized Combination of Images at K ′ and K s , we exclude stellar or massive brown dwarf companions within 300 mas of the Herbig Ae star, and all but planetary mass companions exterior to 0. ′′ 5. We reach 5-σ contrasts limiting companions to planetary masses, 3-4 M J at 1. ′′ 0 and 2 M J at 1. ′′ 55 using the COND models. Collectively, these data strengthen the case for MWC 758 already being a young planetary system. Subject headings: circumstellar matter instrumentation: high angular resolution polarization planetary systems: protoplanetary disks stars: individual (MWC 758) waves

Using the ASTE 10 m submillimeter telescope and the 1.4 m Infrared Survey Facility (IRSF), we performed an extensive outflow survey in the Orion Molecular Cloud -2 and -3 region. Our survey, which includes 41 potential star-forming sites, has been newly compiled using multi-wavelength data based on millimeter-and submillimeter-continuum observations as well as radio continuum observations. From the CO (3-2) observations performed with the ASTE 10 m telescope, we detected 14 CO molecular outflows, seven of which were newly identified. This higher detection rate, as compared to previous CO (1-0) results in the same region, suggests that CO (3-2) may be a better outflow tracer. Physical properties of these outflows and their possible driving sources were derived. Derived parameters were compared with those of CO outflows in low-and high-mass starforming regions. We show that the CO outflow momentum correlates with the bolometric luminosity of the driving source and with the envelope mass, regardless of the mass of the driving sources. In addition to these CO outflows, seven sources having NIR features suggestive of outflows were also identified.Subject headings: ISM: clouds -ISM: individual (OMC-2/3) -stars: formation -ISM: outflows -ISM: molecules -radio lines: ISM CO (3-2) emission with the ASTE telescope. The ASTE (Atacama Submillimeter Telescope Experiment) telescope equipped with a 345 GHz receiver is one of the most powerful facilities with which to seek molecular outflows over a wide field of views. The ASTE telescope in the "On-The-Fly" mapping mode enabled us to observe the entire region of OMC-2/3 with a high sensitivity limit (i.e., corresponding mass of the sensitivity limit is ∼10 −4 M ⊙ ). The CO (3-2) emission exclusively traces higher temperature gas (≥ 33 K). Our CO (3-2) results are compared with previous CO (1-0) results. We also show deep JHK s images taken by the Simultaneous Three-Color InfrarRed Imager for Unbiased Survey camera (SIRIUS) on Infrared Survey Facility (IRSF), which provide us with the distributions of faint reflection nebulae, chains of knots, and jet-like features. Furthermore, we also used the archived 24 µm data obtained by the infrared camera MIPS (Multiband Imaging Photometer) on the infrared space telescope Spitzer, which are sensitive to hot dusty components with a temperature of ∼ 150 K, and probably trace 100 AU scale innermost envelopes/circumstellar disks associated with the central heating sources.The details of the observations of the submillimeter CO (3-2) emission and the near infrared JHKs-bands are presented in Section 2. In Section 3, we show the results of the outflow survey. Data analysis of the CO (3-2) outflows is shown in Section 4 and properties of the outflow driving sources are described in Section 5. In Section 6, we discuss the physical properties of the CO outflows in OMC-2/3 and compare them with outflows associated with low-to high-mass YSOs in previous studies. Finally, Section 7 summarizes the paper. OBSERVATIONS AND DATA REDUCTION CO (3-2) observ...

Direct Imaging of a Cold Jovian Exoplanet in Orbit around the Sun-like Star GJ 504Kuzuhara, M.; et al., [Unknown]; Thalmann, C.D. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 13 May 2018The Astrophysical Journal, 774:11 (18pp) ABSTRACT Several exoplanets have recently been imaged at wide separations of >10 AU from their parent stars. These span a limited range of ages (<50 Myr) and atmospheric properties, with temperatures of 800-1800 K and very red colors (J − H > 0.5 mag), implying thick cloud covers. Furthermore, substantial model uncertainties exist at these young ages due to the unknown initial conditions at formation, which can lead to an order of magnitude of uncertainty in the modeled planet mass. Here, we report the direct-imaging discovery of a Jovian exoplanet around the Sun-like star GJ 504, detected as part of the SEEDS survey. The system is older than all other known directly imaged planets; as a result, its estimated mass remains in the planetary regime independent of uncertainties related to choices of initial conditions in the exoplanet modeling. Using the most common exoplanet cooling model, and given the system age of 160 +350 −60 Myr, GJ 504b has an estimated mass of 4 +4.5 −1.0 Jupiter masses, among the lowest of directly imaged planets. Its projected separation of 43.5 AU exceeds the typical outer boundary of ∼30 AU predicted for the core accretion mechanism. GJ 504b is also significantly cooler (510 +30 −20 K) and has a bluer color (J − H = −0.23 mag) than previously imaged exoplanets, suggesting a largely cloud-free atmosphere accessible to spectroscopic characterization. Thus, it has the potential of providing novel insights into the origins of giant planets as well as their atmospheric properties.