12A abstracts

SMARTS

SMARTS Observations of Fermi/LAT Monitored Blazars
C.D. Bailyn, C.M. Urry, M. Buzton, E. Bonning, R. Chatterjee, J. Isler

We propose to extend our ongoing program of SMARTS studies of blazars observed by Fermi/LAT. The Yale SMARTS team provides optical/IR photometry similar in cadence, duration, precision and homogeneity to the data provided by Fermi in GeV energies, as well as regular, bi-monthly spectroscopy of the brighter sources. In combination, these data are able to constrain both characteristic peaks of blazar spectral energy distributions. In addition, the optical emission lines allow unprecendented constraint on the disk and jet emission in these sources. Intra-night optical/IR monitoring can also help to constrain the size of the !-emitting region.

SMARTS Observations of X-ray Binaries
C.D. Bailyn, M. Buxton, R. Chatterjee, R. MacDonald, J. Orosz, J. McClintock, R. Remillard

We propose to continue our long-term campaign to monitor x-ray binaries with the SMARTS 1.3m and 1.5m telescopes. The x-ray binaries we study are systems in which a compact object is accreting material from a Roche-lobe-filling secondary star; they can exist in any of several x-ray states, including quiescence and several types of outburst. Our monitoring program studies these objects while in x-ray quiescence, in order to learn more about their optical properties, binary parameters, and accretion flows. In addition to providing long-time-baseline light curves for a dozen objects, data from this project has shown that x-ray quiescent systems are often not completely stable and predictable—they can exhibit different optical states, with “active” being both brighter and more variable than “passive.” Our data has also shown that there are often optical precursors to x-ray outbursts, and that in some systems one can determine the x-ray state of the object simply by examining the optical and IR data. None of these discoveries would be possible with a onetime observing run. This long-term program has also provided data for many student and postdoc projects, including at least one undergraduate senior project a year for the past several years, and one ongoing PhD thesis.

The CHIRON Planet Search for Rocky Planets
M. Giguere, D. Fischer

While the occurrence of Jupiter-mass planets around nearby stars is fairly well known, there is currently a significant discrepancy between several published values for the occurrence of low-mass planets (Howard et al. 2010a, Howard et al. 2011a, Mayor et al. 2011). While the amplitude of the wobble induced in solar-type stars by orbiting very low-mass planets is below the detection capabilities of HIRES on Keck, or any other instrument available to the US community, CHIRON has demonstrated that it is capable of detecting these planets through it’s sub-m s−1 precision overlong time periods. We propose to use the CHIRON spectrometer on the CTIO-1.5m to determine the occurrence of low-mass planets and the frequency of low-mass planets in multi-planet systems. Knowing the mass and period distributions of planetary systems is necessary in order to understand planet formation and test formation theories. The low-mass planets around nearby stars we aim to discover with CHIRON will also be crucial for the development of future missions to detect the atmospheres of planets orbiting nearby stars and the eventual determination of the occurrence of habitable worlds.

Astrometric and Photometric Follow-up of the La Silla-QUEST Kuiper-Belt survey
D.Rabinowitz, S. Tourtellote, M. Schwamb, E. Hadjiyska

We propose to continue our astrometric and photometric follow-up of the distant solar-system bodies discovered by Yale’s La Silla - QUEST survey (LSQ). Studying the nature of these relic planetesimals constrains their composition, and also the formation and evolution of the solar system. LSQ is detecting several new distant objects per month. In the past year, we discovered an exciting new object of unusually high inclination (2010 WG09) which could be from the same source population as the mysterious, distant object Sedna. We also found a pair of TNOs with unusually similar orbits and colors (2010 FD49 and 2010 FE49). This could be the first discovery of an ”ionized” binary in the Kuiper Belt – two objects that once formed a binary but were later separated by the gravitional interaction with a third large body. We are using ANDICAM on the SMARTS 1.3m to characterise these new objects, and to measure the orbit, brightness, and color of other new discoveries. The largest objects, and those with the most peculiar properties are being followed extensively to determine their rotation state and surface composition. We are also combining these results with visible and near-IR observations we are making with the NTT at La Silla and the VLT at Paranal.

WIYN

The Host Galaxies of Dust-Reddened Quasars
E. Glikman, B. Simmons, C. M. Urry, K. Schawinski

We propose to take advantage of the superior imaging quality offered by the WIYN observatory to study the host galaxies of heavily reddened quasars. These objects may represent a unique evolutionary stage in merger-driven quasar/galaxy co-evolution where the enshrouded, obscured quasar is shedding its cocoon and is beginning to reveal itself. The dust-reddening of the quasars makes it possible to study the hosts at rest-frame optical-UV wavelengths more easily than the hosts of unobscured quasars of similar bolometric luminosity. Our target list spans a redshift range of 0.2 − 2.3 requiring both optical and near-IR imaging, depending on the source. We will look for evidence of merging and interaction, multiple nuclei, and star formation activity to better understand the role and time scales of mergers in galaxy/SMBH co-formation and co-evolution.

A Complete Sample of X-Ray-Selected AGN in Stripe 82
E. Glikman, C.M. Urry, S. LaMassa, K. Schawinski

We propose to complete a census of supermassive black hole growth by analyzing ∼ 12 deg 2 of archival XMM-Newton data matched to SDSS objects in Stripe 82. The large volume accessible with this survey as well as the hard X-ray response of XMM-Newton provides access to rare objects (e.g., high L, high z, high mass). We will use this complete sample of X-ray-selected AGN, which is least sensitive to obscuration, to advance several key science goals: We will (1) measure the bright end of the X-ray luminosity function of QSOs, which is surprisingly poorly measured in X-rays; (2) study the co-evolution of black holes and their host galaxies, using the superior imaging available in this area; (3) obtain a full, multiwavelength census of X-ray bright AGN, using the extensive multiwavelength data in this area.

Finding the Parent of the ‘Orphan Tidal Stream’: accretion and structure formation in the Milky Way Halo
N. Kallivayalil, M. Geha, A. Bonaca

We propose to obtain radial velocities for stars in the Orphan stellar stream in the Milky Way with WIYN/HYDRA. Tidal streams are emerging as active sites to disentangle the processes of structure formation in the Milky Way because they contain information about the internal dynamics of the projenitor as well as information about the phase-space structure of dark matter in the Milky Way halo. While the theory of tidal disruption has seen a flood of work recently, the 3-D velocities needed to test these theories are largely missing. Here we will specifically target parts of the Orphan stream for which proper motion data is already in hand. Combination of the radial velocities and proper motions will allow us to determine the nature of Orphan’s parent (whether a globular cluster or a satellite galaxy), put limits on whether the ‘lumpiness’ of the Milky Way halo can affect the velocity structure of streams, and calculate the orbit of the stream, thereby constraining the mass and shape of the Milky Way gravitational otential.

Multi-Band Deep Imaging of “Hidden” Broad-Line-Region Active Galaxies
K. Schawinski, C. M. Urry, M. Sarzi, S. K. Yi, K. Oh, H. Jeong

We newly found thousands of “hidden” broad-line-region galaxies (BLRs) from the Sloan Digital Sky Survey DR7 under the most detailed analysis of galaxy spectra. This increases the current estimate for the number of BLR galaxies by a factor of almost 10. These objects with low-luminosity active galactic nucleus (AGN) have not been detected well due to their weak signature. The poorresolution SDSS images are giving some clues that BLRs are in varieties of galaxy morphological types and a very high fraction of them is merger or interacting system. Recent work on SDSS AGN has shown that morphology is a key parameter in the galaxy-black hole connection and galaxy evolution. The poor seeing of SDSS images, however, makes it hard to discern their morphological types and complete further analysis. Previous use of WIYN+MiniMo convinced that its superb seeing conditions make it possible to search for fine structures. We observed 10 galaxies in the spring (2011), but this sample is too small for robust statistics. We theefore propose to observe ∼20 more BLRs with WIYN+MiniMo. By combining WIYN imaging data with existing SDSS spectral data, we aim to detect merger features to test the hypothesis of a high merger fraction and determine the morphology of the host galaxies. In addition, all targets were observed by GALEX and it allows us to see further analysis such as star formation features. Moreover, detailed light profile fitting using GALFIT and GIM2D will be used to find anomalous light distribution including central AGN activities. The WIYN data give us a privileged glimpse into the future of BLR AGN host galaxies.

Diffraction-Limited Imaging with DSSI: Surveying Hipparcos Binaries and Vetting Candidate Exoplanet Host Stars
W. van Altena, E. Horch, S. Howell, D. Fischer

We propose two complementary projects best handled in the same run with the DSSI speckle camera, a visitor instrument currently at WIYN. The first project is a continuation of our effort to provide high-precision relative astrometry and differential photometry of binary stars. The main goal is to characterize a volume-limited sample of binaries within 250 pc of the Sun. With the full data set, it will be possible to make a major contribution to the main-sequence mass-luminosity relation especially for low-mass and metal-poor stars, as well as to conduct dozens of very sensitive tests of the details of stellar evolution models and to understand the statistics of thin and thick disk binaries. The latter is important in learning how to use binaries as probes of galactic structure and evolution. The second project is to obtain diffraction-limited images of candidate exoplanet host stars as a part of ground based follow-up for Kepler and including targets identified through the Planethunters citizen science project. Th photometric signal of an apparent planetary transit can be mimicked by e.g. a background eclipsing binary star very close to the Kepler target. With the high resolution that the DSSI camera provides, a substantial section of parameter space for this type of false positive can be ruled out. If a star has an exoplanet and has a close companion star, then the light due to the second star must be known before the light curve of the transit can be properly interpreted. DSSI can do this job as well with its proven photometric precision.

Keck

Yale Exoplanet Search
D. Fischer, J. Spronck, M. Giguere, J. Brewer, J. Moriarity, J. O'Rourke

In the past year, the exoplanets from Kepler and Doppler surveys have demonstrated that SuperEarth and Neptune (SEN) mass planets are common: at least 25% of stars have low mass planets with orbital periods less than 50d. Late type stars are ideal for the detection of these exoplanets: stellar noise is a minimum and the low stellar mass results in a larger reflex velocity. We have defined a subset of 30 bright stars from the M2K program that already have a heritage of ∼10 observations. The formal measurement precision is about 1.4 m s −1, and the mean velocity rms of this sample is 9 m s−1, making these prime targets for a search for short-period SEN planets. We are also following planet candidates from a sample of metal-rich stars and using time to investigate planet candidates discovered by users on PlanetHunters.com.

Black holes at the centers of nearby dwarf galaxies
C. M. Urry, K. Schawinski, E. Moran, P. Natarajan

Using a distance-limited subset of the SDSS DR7, we have identified a new sample of nearby, lowmass dwarf galaxies that contain AGNs. The study of such objects is crucial for gaining insight into the origins of (a) the black hole/host galaxy scaling relations observed for massive, bulgedominated galaxies and (b) the “seeds” of supermassive black holes that formed at earlier times. Our sample consists of 20 galaxies fainter than Mg = −18.3 and with stellar masses below 10 10 M⊙. Collectively, they are the least massive galaxies known to contain central black holes, and the black holes themselves must be in the intermediate-mass range (MBH = 10 3 –10 6 M⊙). We request two nights of Keck II/ESI time to obtain high resolution, high S/N spectra of our targets, which will be used to measure their central stellar velocity dispersions σ*. In more massive systems, σ* correlates tightly with black hole mass. A comparison of the range of σ* values we obtain to cosmological simulations of the evolution of “light” and “heavy” black hole seeds will shed light on the mechanism by which BH seeds formed.

The Star-Forming Ancestors of Elliptical Galaxies
P. van Dokkum, E. Nelson, J. Leja, G. Brammer, R. Skelton

Many studies over the past few years have identified a population of compact, massive galaxies at redshifts 1.5 < z < 2.5 with old stellar populations. These compact galaxies essentially disappear at redshifts z < 1: they are thought to have gradually increased their sizes since z ∼ 2 through mergers, forming the cores of giant elliptical galaxies today. The stars in these dense galaxies must have formed at some point in the past, presumably in extremely vigorous star bursts accompanied by significant black hole growth. Many groups are now searching for these star forming progenitors, as their properties are expected to be spectacular. Our 248-orbit 3D-HST Treasury program provides near-IR grism spectroscopy for thousands of high redshift galaxies. We have searched the initial ∼ 50 % of 3D-HST data to identify compact, massive galaxies with strong emission lines and identified six such objects. These are the best candidates for being direct ancestors of the enigmatic compact massive galaxies at high redshift – ad of today’s elliptical galaxies. To confirm this, we need to measure the kinematics of these galaxies: if the galaxies are as massive and as dense as we think they are, predicted rotation speeds are in excess of 400 km/s. The HST grism spectra have very poor spectral resolution and cannot be used to measure kinematics. Here we request two nights with NIRSPEC to measure the kinematics of these six objects, to test whether they could indeed be the long-sought star-forming cores of present-day elliptical galaxies.