Simulations for Multi-Object Spectrograph Planet Surveys

Radial velocity surveys for extra-solar planets generally require substantial amounts of large telescope time in order to monitor a sufficient number of stars. Two of the aspects which can limit such surveys are the single-object capabilities of the spectrograph, and an inefficient observing strategy for a given observing window. In addition, the detection rate of extra-solar planets using the radial velocity method has thus far been relatively linear with time. With the development of various multi-object Doppler survey instruments, there is growing potential to dramatically increase the detection rate using the Doppler method. Several of these instruments have already begun usage in large scale surveys for extra-solar planets, such as FLAMES on the VLT and Keck ET on the Sloan 2.5m wide-field telescope. In order to plan an effective observing strategy for such a program, one must examine the expected results based on a given observing window and target selection. We present simulations of the expected results from a generic multi-object survey based on calculated noise models and sensitivity for the instrument and the known distribution of exoplanetary system parameters. We have developed code for automatically sifting and fitting the planet candidates produced by the survey to allow for fast follow-up observations to be conducted. The techniques presented here may be applied to a wide range of multi-object planet surveys.Comment: 15 pages, 10 figures, accepted for publication in MNRA

Unveiling Su Aurigae in the near Infrared: New high spatial resolution results using Adaptive Optics

We present here new results on circumstellar nebulosity around SU Aurigae, a T-Tauri star of about 2 solar mass and 5 Myrs old at 152 pc in the J, H and K bands using high resolution adaptive optics imaging (0\farcs30) with the Penn state IR Imaging Spectrograph (PIRIS) at the 100 inch Mt. Wilson telescope. A comparison with HST STIS optical (0.2 to 1.1 micron) images shows that the orientation of the circumstellar nebulosity in the near-IR extends from PAs 210 to 270 degrees in H and K bands and up to 300 degrees in the J band. We call the circumstellar nebulosity seen between 210 to 270 degrees as 'IR nebulosity'. We find that the IR nebulosity (which extends up to 3.5 arcsecs in J band and 2.5 arcsecs in the K band) is due to scattered light from the central star. The IR nebulosity is either a cavity formed by the stellar outflows or part of the circumstellar disk. We present a schematic 3-dimensional geometrical model of the disk and jet of SU Aur based on STIS and our near-IR observations. According to this model the IR nebulosity is a part of the circumstellar disk seen at high inclination angles. The extension of the IR nebulosity is consistent with estimates of the disk diameter of 50 to 400 AU in radius, from earlier mm, K band interferometric observations and SED fittings.Comment: Accepted for publications in the Astronomical Journal, to appear in the May issue of the Journa

Incidence of HI 21-cm absorption in strong FeII systems at 0.5<z<1.50.5<z<1.5

We present the results from our search for HI 21-cm absorption in a sample of 16 strong FeII systems ($W_{\rm r}$(MgII $\lambda2796$) $\ge1.0$ \AA\ and $W_{\rm r}$(FeII $\lambda2600$) or $W_{\rm FeII}$ $\ge1$ \AA) at $0.5<z<1.5$ using the Giant Metrewave Radio Telescope and the Green Bank Telescope. We report six new HI 21-cm absorption detections from our sample, which have increased the known number of detections in strong MgII systems at this redshift range by $\sim50$%. Combining our measurements with those in the literature, we find that the detection rate of HI 21-cm absorption increases with $W_{\rm FeII}$, being four times higher in systems with $W_{\rm FeII}$ $\ge1$ \AA\ compared to systems with $W_{\rm FeII}$ $<1$ \AA. The $N$(HI) associated with the HI 21-cm absorbers would be $\ge 2 \times 10^{20}$ cm$^{-2}$, assuming a spin temperature of $\sim500$ K (based on HI 21-cm absorption measurements of damped Lyman-$\alpha$ systems at this redshift range) and unit covering factor. We find that HI 21-cm absorption arises on an average in systems with stronger metal absorption. We also find that quasars with HI 21-cm absorption detected towards them have systematically higher $E(B-V)$ values than those which do not. Further, by comparing the velocity widths of HI 21-cm absorption lines detected in absorption- and galaxy-selected samples, we find that they show an increasing trend (significant at $3.8\sigma$) with redshift at $z<3.5$, which could imply that the absorption originates from more massive galaxy haloes at high-$z$. Increasing the number of HI 21-cm absorption detections at these redshifts is important to confirm various trends noted here with higher statistical significance.Comment: 17 pages, 10 figures, 8 tables, accepted for publication in MNRA

Evolving Network With Different Edges

We proposed an evolving network model constituted by the same nodes but different edges. The competition between nodes and different links were introduced. Scale free properties have been found in this model by continuum theory. Different network topologies can be generated by some tunable parameters. Simulation results consolidate the prediction.Comment: 14 pages, 9 figures, some contents revised, fluctuation of x degree adde

Quantum Entanglement and Teleportation in Higher Dimensional Black Hole Spacetimes

We study the properties of quantum entanglement and teleportation in the background of stationary and rotating curved space-times with extra dimensions. We show that a maximally entangled Bell state in an inertial frame becomes less entangled in curved space due to the well-known Hawking-Unruh effect. The degree of entanglement is found to be degraded with increasing the extra dimensions. For a finite black hole surface gravity, the observer may choose higher frequency mode to keep high level entanglement. The fidelity of quantum teleporation is also reduced because of the Hawking-Unruh effect. We discuss the fidelity as a function of extra dimensions, mode frequency, black hole mass and black hole angular momentum parameter for both bosonic and fermionic resources.Comment: 15 pages, 10 figures,contents expande

Sustainable housing - a case study of heritage building in Hangzhou China

Surrounded by high-rise buildings, some two-storey buildings with black roofs are sited along the Xiaohe (Little River) in the north of Hangzhou, China. The buildings were originally built in the late Qing Dynasty (late 19th century) and restored in 2007 by the Hangzhou municipal government. The architectural materials used in the buildings are mainly concrete for the ground floor and timber to the first floor. Three buildings located at Xiaohe Historical Street were investigated to establish whether traditional buildings performed as well as modern buildings. Hourly temperature and humidity readings from September 2009 to August 2010 were recorded for the selected houses. It was concluded through comparisons that the restored heritage buildings provided similar thermal comfort and conditions to modern buildings

VConv-DAE: Deep Volumetric Shape Learning Without Object Labels

With the advent of affordable depth sensors, 3D capture becomes more and more ubiquitous and already has made its way into commercial products. Yet, capturing the geometry or complete shapes of everyday objects using scanning devices (e.g. Kinect) still comes with several challenges that result in noise or even incomplete shapes. Recent success in deep learning has shown how to learn complex shape distributions in a data-driven way from large scale 3D CAD Model collections and to utilize them for 3D processing on volumetric representations and thereby circumventing problems of topology and tessellation. Prior work has shown encouraging results on problems ranging from shape completion to recognition. We provide an analysis of such approaches and discover that training as well as the resulting representation are strongly and unnecessarily tied to the notion of object labels. Thus, we propose a full convolutional volumetric auto encoder that learns volumetric representation from noisy data by estimating the voxel occupancy grids. The proposed method outperforms prior work on challenging tasks like denoising and shape completion. We also show that the obtained deep embedding gives competitive performance when used for classification and promising results for shape interpolation