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Caltech Authors (147.820 recursos)

Repository of works by Caltech published authors.

Group = Infrared Processing and Analysis Center (IPAC)

Mostrando recursos 1 - 20 de 1.842

  1. The Herschel Orion Protostar Survey: Luminosity and Envelope Evolution

    Fischer, William J.; Megeath, S. Thomas; Furlan, Elise; Ali, Babar; Stutz, Amelia M.; Tobin, John J.; Osorio, Mayra; Stanke, Thomas; Manoj, P.; Poteet, Charles A.; Booker, Joseph J.; Hartmann, Lee; Wilson, Thomas L.; Myers, Philip C.; Watson, Dan M.
    The Herschel Orion Protostar Survey obtained well-sampled 1.2–870 μm spectral energy distributions (SEDs) of over 300 protostars in the Orion molecular clouds, home to most of the young stellar objects (YSOs) in the nearest 500 pc. We plot the bolometric luminosities and temperatures for 330 Orion YSOs, 315 of which have bolometric temperatures characteristic of protostars. The histogram of the bolometric temperature is roughly flat; 29% of the protostars are in Class 0. The median luminosity decreases by a factor of four with increasing bolometric temperature; consequently, the Class 0 protostars are systematically brighter than the Class I protostars, with...

  2. The Complete Calibration of the Color-Redshift Relation (C3R2) Survey: Survey Overview and Data Release 1

    Masters, Daniel; Stern, Daniel; Cohen, Judith G.; Capak, Peter; Rhodes, Jason; Castander, Francisco; Paltani, Stephane
    A key goal of the Stage IV dark energy experiments Euclid, LSST and WFIRST is to measure the growth of structure with cosmic time from weak lensing analysis over large regions of the sky. Weak lensing cosmology will be challenging: in addition to highly accurate galaxy shape measurements, statistically robust and accurate photometric redshift (photo-z) estimates for billions of faint galaxies will be needed in order to reconstruct the three-dimensional matter distribution. Here we present an overview of and initial results from the Complete Calibration of the Color-Redshift Relation (C3R2) survey, designed specifically to calibrate the empirical galaxy color-redshift relation to the Euclid depth. These redshifts will also be...

  3. Growing supermassive black holes in the late stages of galaxy mergers are heavily obscured

    Ricci, C.; Bauer, F. E.; Treister, E.; Schawinski, K.; Privon, G. C.; Blecha, L.; Arevalo, P.; Armus, L.; Harrison, F. A.; Ho, L. C.; Iwasawa, K.; Sanders, D. B.; Stern, D.
    Mergers of galaxies are thought to cause significant gas inflows to the inner parsecs, which can activate rapid accretion on to supermassive black holes (SMBHs), giving rise to active galactic nuclei (AGN). During a significant fraction of this process, SMBHs are predicted to be enshrouded by gas and dust. Studying 52 galactic nuclei in infrared-selected local luminous and ultraluminous infrared galaxies in different merger stages in the hard X-ray band, where radiation is less affected by absorption, we find that the amount of material around SMBHs increases during the last phases of the merger. We find that the fraction of Compton-thick (CT, NH ≥ 10^(24) cm^−2) AGN...

  4. An Application of Multi-band Forced Photometry to One Square Degree of SERVS: Accurate Photometric Redshifts and Implications for Future Science

    Nyland, Kristina; Lacy, Mark; Sajina, Anna; Pforr, Janine; Farrah, Duncan; Wilson, Gillian; Surace, Jason; Häußler, Boris; Vaccari, Mattia; Jarvis, Matt
    We apply The Tractor image modeling code to improve upon existing multi-band photometry for the Spitzer Extragalactic Representative Volume Survey (SERVS). SERVS consists of post-cryogenic Spitzer observations at 3.6 and 4.5 μm over five well-studied deep fields spanning 18 deg^2. In concert with data from ground-based near-infrared (NIR) and optical surveys, SERVS aims to provide a census of the properties of massive galaxies out to z ≈ 5. To accomplish this, we are using The Tractor to perform "forced photometry." This technique employs prior measurements of source positions and surface brightness profiles from a high-resolution fiducial band from the VISTA...

  5. On the Relative Sizes of Planets within Kepler Multiple-candidate Systems

    Ciardi, David R.; Fabrycky, Daniel C; Ford, Eric B; Gautier, T. N., III; Howell, Steve B; Lissauer, Jack J; Ragozzine, Darin; Rowe, Jason F
    We present a study of the relative sizes of planets within the multiple-candidate systems discovered with the Kepler mission. We have compared the size of each planet to the size of every other planet within a given planetary system after correcting the sample for detection and geometric biases. We find that for planet pairs for which one or both objects are approximately Neptune-sized or larger, the larger planet is most often the planet with the longer period. No such size-location correlation is seen for pairs of planets when both planets are smaller than Neptune. Specifically, if at least one planet...

  6. The Far Future of Exoplanet Direct Characterization

    Schneider, Jean; Léger, Alain; Fridlund, Malcolm; White, Glenn J.; Eiroa, Carlos; Henning, Thomas; Herbst, Tom; Lammer, Helmut; Liseau, René; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Selsis, Franck; Beichman, Charles; Danchi, William; Kaltenegger, Lisa; Lunine, Jonathan; Stam, Daphne; Tinetti, Giovanna
    We describe future steps in the direct characterization of habitable exoplanets subsequent to medium and large mission projects currently underway and investigate the benefits of spectroscopic and direct imaging approaches. We show that, after third- and fourth-generation missions have been conducted over the course of the next 100 years, a significant amount of time will lapse before we will have the capability to observe directly the morphology of extrasolar organisms.

  7. Complex Spiral Structure in the HD 100546 Transitional Disk as Revealed by GPI and MagAO

    Follette, Katherine B.; Millar-Blanchaer, Maxwell A.; Wallace, J. Kent
    We present optical and near-infrared high-contrast images of the transitional disk HD 100546 taken with the Magellan Adaptive Optics system (MagAO) and the Gemini Planet Imager (GPI). GPI data include both polarized intensity and total intensity imagery, and MagAO data are taken in Simultaneous Differential Imaging mode at Hα. The new GPI H-band total intensity data represent a significant enhancement in sensitivity and field rotation compared to previous data sets and enable a detailed exploration of substructure in the disk. The data are processed with a variety of differential imaging techniques (polarized, angular, reference, and simultaneous differential imaging) in an...

  8. The Astrophysics of Star Formation Across Cosmic Time at ≳10 GHz with the Square Kilometre Array

    Murphy, Eric J.; Sargent, Mark T.; Beswick, Rob J.; Dickinson, Clive; Heywood, Ian; Hunt, Leslie K.; Hyunh, Minh T.; Jarvis, Matt; Karim, Alexander; Krause, Marita; Prandoni, Isabella; Seymour, Nicholas; Schinnerer, Eva; Tabatabaei, Fatemeh S.; Wagg, Jeff
    In this chapter, we highlight a number of science investigations that are enabled by the inclusion of Band 5 (4.6-13.8 GHz) for SKA1-MID science operations, while focusing on the astrophysics of star formation over cosmic time. For studying the detailed astrophysics of star formation at highredshift, surveys at frequencies ≳10 GHz have the distinct advantage over traditional ~1.4 GHz surveys as they are able to yield higher angular resolution imaging while probing higher rest frame frequencies of galaxies with increasing redshift, where emission of star-forming galaxies becomes dominated by thermal (free-free) radiation. In doing so, surveys carried out at ≳10 GHz provide...

  9. Discovery of a Mid-infrared Echo from the TDE Candidate in the Nucleus of ULIRG F01004−2237

    Dou, Liming; Wang, Tinggui; Yan, Lin; Jiang, Ning; Yang, Chenwei; Cutri, Roc M.; Mainzer, Amy; Peng, Bo
    We present the mid-infrared (MIR) light curves (LCs) of a tidal disruption event candidate in the center of a nearby ultraluminous infrared galaxy F01004−2237 using archival WISE and NEOWISE data from 2010 to 2016. At the peak of the optical flare, F01004−2237 was IR quiescent. About three years later, its MIR fluxes have shown a steady increase, rising by 1.34 and 1.04 mag in 3.4 and 4.6 μm up to the end of 2016. The host-subtracted MIR peak luminosity is 2–3 × 10^(44) erg s^(−1). We interpret the MIR LCs as an infrared echo, i.e., dust reprocessed emission of the...

  10. Periodic Photometric Variability in the Becklin-Neugebauer Object

    Hillenbrand, Lynne A.; Carpenter, John M.; Skrutskie, M. F.
    The Becklin-Neugebauer object (BN) in the Orion Nebula cluster is a well-studied, optically invisible, infrared-bright young stellar object that is thought to be an intermediate-mass protostar. We report here that BN exhibited nearly sinusoidal periodic variability at the near-infrared H and K_s bands during a 1 month observing campaign in 2000 March/April. The period was 8.28 days, and the peak-to-peak amplitude was ~0.2 mag. Plausible mechanisms for producing the observed variability characteristics are explored.

  11. Characterizing Dust Attenuation in Local Star-forming Galaxies: Near-infrared Reddening and Normalization

    Battisti, A. J.; Calzetti, D.; Chary, R.-R.
    We characterize the near-infrared dust attenuation for a sample of ~5500 local (z ≾ 0.1) star-forming galaxies and obtain an estimate of their average total-to-selective attenuation k(λ). We utilize data from the United Kingdom Infrared Telescope and the Two-Micron All Sky Survey, which is combined with previously measured UV–optical data for these galaxies. The average attenuation curve is slightly lower in the far-ultraviolet than in local starburst galaxies by roughly 15% but appears similar at longer wavelengths with a total-to-selective normalization of R_V = 3.67_(-0.35)^(+0.44). Under the assumption of energy balance, the total attenuated energy inferred from this curve is...

  12. Near-infrared MOSFIRE Spectra of Dusty Star-forming Galaxies at 0.2 < z < 4

    Casey, Caitlin M.; Cooray, Asantha; Killi, Meghana; Capak, Peter; Chen, Chian-Chou; Hung, Chao-Ling; Kartaltepe, Jeyhan; Sanders, D. B.; Scoville, N. Z.
    We present near-infrared and optical spectroscopic observations of a sample of 450 and 850 μm-selected dusty star-forming galaxies (DSFGs) identified in a 400 arcmin^2 area in the COSMOS field. Thirty-one sources of the 114 targets were spectroscopically confirmed at 0.2 < z < 4, identified primarily in the near-infrared with Keck MOSFIRE and some in the optical with Keck LRIS and DEIMOS. The low rate of confirmation is attributable both to high rest-frame optical obscuration in our targets and limited sensitivity to certain redshift ranges. The median spectroscopic redshift is 〈Z_(spec)〉 =1.55 ± 0.14, comparable to 〈Z_(phot)〉 = 1.50 ±...

  13. Reverberation Mapping of Optical Emission Lines in Five Active Galaxies

    Fausnaugh, M. M.; Adams, S. M.
    We present the first results from an optical reverberation mapping campaign executed in 2014 targeting the active galactic nuclei (AGNs) MCG+08-11-011, NGC 2617, NGC 4051, 3C 382, and Mrk 374. Our targets have diverse and interesting observational properties, including a "changing look" AGN and a broad-line radio galaxy. Based on continuum-Hβ lags, we measure black hole masses for all five targets. We also obtain Hγ and He ii λ4686 lags for all objects except 3C 382. The He ii λ4686 lags indicate radial stratification of the BLR, and the masses derived from different emission lines are in general agreement. The...

  14. Confirmation of Large Super-fast Rotator (144977) 2005 EC_(127)

    Chang, Chan-Kao; Lin, Hsing-Wen; Ip, Wing-Huen; Lin, Zhong-Yi; Kupfer, Thomas; Prince, Thomas A.; Ye, Quan-Zhi; Laher, Russ R.; Lee, Hee-Jae; Moon, Hong-Kyu
    (144977) 2005 EC_(127) is a V-/A-type inner-main-belt asteroid with a diameter of 0.6 ± 0.1 km. Asteroids of this size are believed to have rubble-pile structure, and therefore cannot have a rotation period shorter than 2.2 hr. However, our measurements show that asteroid 2005 EC_(127) completes one rotation in 1.65 ± 0.01 hr with a peak-to-peak light-curve variation of ~0.5 mag. Therefore, this asteroid is identified as a large super-fast rotator. Either a rubble-pile asteroid with a bulk density of ρ ~ 6 g cm^(−3) or an asteroid with an internal cohesion of 47 ± 30 Pa can explain 2005...

  15. Far‐Infrared Observations of Radio Quasars and FR II Radio Galaxies

    Shi, Y.; Rieke, G. H.; Hines, D. C.; Neugebauer, G.; Blaylock, M.; Rigby, J.; Egami, E.; Gordon, K. D.; Alonso‐Herrero, A.
    We report MIPS photometry of 20 radio-loud quasars and galaxies at 24 and 70 μm (and of five at 160 μm). We combine this sample with additional sources detected in the far-infrared by IRAS and ISO for a total of 47 objects, including 23 steep-spectrum type I AGNs: radio-loud quasars and broad-line radio galaxies; and 24 type II AGNs: narrow-line and weak-line FR II radio galaxies. Of this sample, the far-infrared emission of all but 3C 380 appears to be dominated by emission by dust heated by the AGN and by star formation. The AGN appears to contribute more than...

  16. A Herschel Space Observatory Spectral Line Survey of Local Luminous Infrared Galaxies from 194 to 671 Microns

    Lu, Nanyao; Zhao, Yinghe; Diaz-Santos, Tanio; Xu, C. Kevin; Gao, Yu; Armus, Lee; Isaak, Kate G.; Mazzarella , Joseph M.; van der Werf, Paul P.; Appleton, Philip N.; Charmandaris, Vassilis; Evans, Aaron S.; Howell, Justin; Iwasawa, Kazushi; Leech, Jamie; Lord, Steven; Petric, Andreea O.; Privon, George C.; Sanders, David B.; Schulz, Bernhard; Surace, Jason A.
    We describe a Herschel Space Observatory 194–671 μm spectroscopic survey of a sample of 121 local luminous infrared galaxies and report the fluxes of the CO J to J–1 rotational transitions for 4 ⩽ J ⩽ 13, the [N ii] 205 μm line, the [C i] lines at 609 and 370 μm, as well as additional and usually fainter lines. The CO spectral line energy distributions (SLEDs) presented here are consistent with our earlier work, which was based on a smaller sample, that calls for two distinct molecular gas components in general: (i) a cold component, which emits CO lines...

  17. Far-ultraviolet to Near-infrared Spectroscopy of a Nearby Hydrogen-poor Superluminous Supernova Gaia16apd

    Yan, Lin; Quimby, R.; Gal-Yam, A.; Brown, P.; Blagorodnova, N.; Ofek, E. O.; Lunnan, R.; Cooke, J.; Cenko, S. B.; Jencson, J.; Kasliwal, M.
    We report the first maximum-light far-ultraviolet (FUV) to near-infrared (NIR) spectra (1000 Å − 1.62 μm, rest) of a hydrogen-poor superluminous supernova, Gaia16apd. At z = 0.1018, it is the second closest and the UV brightest SLSN-I, with 17.4 mag in Swift UVW2 band at −11 days pre-maximum. The coordinated observations with HST, Palomar, and Keck were taken at −2 to +25 days. Assuming an exponential (or t^2) form, we derived the rise time of 33 days and the peak bolometric luminosity of 3 × 10^(44) erg s^(−1). At the maximum, the photospheric temperature and velocity are 17,000 K and...

  18. Faint-source-star planetary microlensing: the discovery of the cold gas-giant planet OGLE-2014-BLG-0676Lb

    Rattenbury, N. J.; Calchi Novati, S.
    We report the discovery of a planet – OGLE-2014-BLG-0676Lb– via gravitational microlensing. Observations for the lensing event were made by the following groups: Microlensing Observations in Astrophysics; Optical Gravitational Lensing Experiment; Wise Observatory; RoboNET/Las Cumbres Observatory Global Telescope; Microlensing Network for the Detection of Small Terrestrial Exoplanets; and μ-FUN. All analyses of the light-curve data favour a lens system comprising a planetary mass orbiting a host star. The most-favoured binary lens model has a mass ratio between the two lens masses of (4.78 ± 0.13) × 10−3. Subject to some important assumptions, a Bayesian probability density analysis suggests the lens...

  19. ALMA observations of atomic carbon in z ∼ 4 dusty star-forming galaxies

    Bothwell, M. S.; Aguirre, J. E.; Aravena, M.; Bethermin, M.; Bisbas, T. G.; Chapman, S. C.; De Breuck, C.; Gonzalez, A. H.; Greve, T. R.; Hezaveh, Y.; Ma, J.; Malkan, M.; Marrone, D. P.; Murphy, E. J.; Spilker, J. S.; Strandet, M.; Vieira, J. D.; Weiß, A.
    We present Atacama Large Millimeter Array [C i](1 − 0) (rest frequency 492 GHz) observations for a sample of 13 strongly lensed dusty star-forming galaxies (DSFGs) originally discovered at 1.4 mm in a blank-field survey by the South Pole Telescope (SPT). We compare these new data with available [Ci] observations from the literature, allowing a study of the interstellar medium (ISM) properties of ∼30 extreme DSFGs spanning a redshift range 2 < z < 5. Using the [Ci] line as a tracer of the molecular ISM, we find a mean molecular gas mass for SPT-DSFGs of 6.6 × 10^(10) M_⊙. This...

  20. BAT AGN Spectroscopic Survey - IV: Near-Infrared Coronal Lines, Hidden Broad Lines, and Correlation with Hard X-ray Emission

    Lamperti, Isabella; Koss, Michael; Trakhtenbrot, Benny; Schawinski, Kevin; Ricci, Claudio; Oh, Kyuseok; Landt, Hermine; Riffel, Rogério; Rodríguez-Ardila, Alberto; Gehrels, Neil; Harrison, Fiona; Masetti, Nicola; Mushotzky, Richard; Treister, Ezequiel; Ueda, Yoshihiro; Veilleux, Sylvain
    We provide a comprehensive census of the near-infrared (NIR, 0.8–2.4 μm) spectroscopic properties of 102 nearby (z < 0.075) active galactic nuclei (AGN), selected in the hard X-ray band (14–195 keV) from the Swift-Burst Alert Telescope survey. With the launch of the James Webb Space Telescope, this regime is of increasing importance for dusty and obscured AGN surveys. We measure black hole masses in 68 per cent (69/102) of the sample using broad emission lines (34/102) and/or the velocity dispersion of the Ca ii triplet or the CO band-heads (46/102). We find that emission-line diagnostics in the NIR are ineffective at...

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