What Powers the 12 μm Luminosities in AGNs: Spitzer/IRS Spectroscopic Study of the 12 μm Seyfert Sample

We present a mid-IR study of the 12 μm Seyfert sample, using 5-35 μm low-resolution spectroscopy from Spitzer/IRS. Sources in this sample display a wide variety of spectral shapes. We perform an analysis of the continuum emission, the strength of the Polycyclic Aromatic Hydrocarbon (PAH) emission, as well as fine-structure lines, in order to study the mid-IR properties of the local Seyfert galaxies. We find that the equivalent widths of PAHs decrease with increasing dust temperature. We also propose a method to estimate the AGN contribution to the integrated 12 μm emission of the galaxy

The Effects of Relativistic Corrections on Cosmological Parameter Estimations from SZE Cluster Surveys

Sunyaev-Zel'dovich Effect (SZE) cluster surveys are anticipated to yield tight constraints on cosmological parameters such as the equation of state of dark energy. In this paper, we study the impact of relativistic corrections of the thermal SZE on the cluster number counts expected from a cosmological model and thus, assuming that other cosmological parameters are known to high accuracies, on the determination of the $w$ parameter and $\sigma_8$ from a SZE cluster survey, where $w=p/\rho$ with $p$ the pressure and $\rho$ the density of dark energy, and $\sigma_8$ is the rms of the extrapolated linear density fluctuation smoothed over $8\hbox{Mpc}h^{-1}$. For the purpose of illustrating the effects of relativistic corrections, our analyses mainly focus on $\nu=353 \hbox{GHz}$ and $S_{lim}=30\hbox{mJy}$, where $\nu$ and $S_{lim}$ are the observing frequency and the flux limit of a survey, respectively. These observing parameters are relevant to the {\it Planck} survey. It is found that from two measurable quantities, the total number of SZE clusters and the number of clusters with redshift $z\ge 0.5$, $\sigma_8$ and $w$ can be determined to a level of $\pm 1$ and $\pm 8$, respectively, with $1\sigma$ uncertainties from a survey of $10000\hbox{deg}^2$. Relativistic effects are important in determining the central values of $\sigma_8$ and $w$. If we choose the two quantities calculated relativistically from the flat cosmological model with $\sigma_8=0.8284$ and $w=-0.75$ as input, the derived $\sigma_8$ and $w$ would be 0.819 and -0.81, respectively, if relativistic effects are wrongly neglected. The location of the resulting $\sigma_8$ and $w$ in the $\sigma_8-w$ plane is outside the $3\sigma$ region around the real central $\sigma_8$ and $w$.Comment: ApJ in pres

Local Domain-Free Discretization Method and Its Combination with Immersed Boundary Method for Simulation of Fluid Flows

Ph.DDOCTOR OF PHILOSOPH

Public administration research in mainland China and Taiwan: an assessment of journal publications, 1998-2008

10.1111/j.1467-9299.2011.01978.xPublic Administration912261-28

Elemental Abundances of Blue Compact Dwarfs from mid-IR Spectroscopy with Spitzer

We present a study of elemental abundances in a sample of thirteen Blue Compact Dwarf (BCD) galaxies, using the $\sim$10--37$\mu$m high resolution spectra obtained with Spitzer/IRS. We derive the abundances of neon and sulfur for our sample using the infrared fine-structure lines probing regions which may be obscured by dust in the optical and compare our results with similar infrared studies of starburst galaxies from ISO. We find a good correlation between the neon and sulfur abundances, though sulfur is under-abundant relative to neon with respect to the solar value. A comparison of the elemental abundances (neon, sulfur) measured from the infrared data with those derived from the optical (neon, sulfur, oxygen) studies reveals a good overall agreement for sulfur, while the infrared derived neon abundances are slightly higher than the optical values. This indicates that either the metallicities of dust enshrouded regions in BCDs are similar to the optically accessible regions, or that if they are different they do not contribute substantially to the total infrared emission of the host galaxy.Comment: 11 pages, 6 figures, accepted by Ap

High-Throughput Single Extracellular Vesicle Profiling

Extracellular vesicles (EVs) are heterogeneous due to their cell of origins, biogenesis, stimuli in the microenvironment and so on. Single EV analysis is required for the study of EV heterogeneity. Besides the investigation of EV biology, single EV analysis technologies are promising approach for liquid biopsy, which relies on the detection of biomarker EVs readily available in body fluids but in trace amount. However, EVs are nano-scaled structures, which beyond the resolution of conventional technologies like optical microscopes, flow cytometers and so on. In this chapter, we will discuss advanced strategies for studying single EVs, including single EV imaging systems, flow cytometers, nano-sensing technologies and single EV barcoding assay

The Philosophical Connotations of Popular Aerobics: Illustrated by the Case of Lesmills

This paper applies the introspection method to explore the philosophical connotations of popular aerobics by analyzing the case of Lesmills. It argues that people could maintain self-integrity and experience the sense of existence during popular aerobics exercises. Popular aerobics exercises help people increase their strength and courage substantially in addition to sharpening and deepening their human sensibility. In conclusion, this paper advocates and urges the popularization of aerobics exercises for their profound philosophical values

The Energetics of Molecular Gas in NGC 891 from H_2 and Far-infrared Spectroscopy

We have studied the molecular hydrogen energetics of the edge-on spiral galaxy NGC 891, using a 34 position map in the lowest three pure rotational H_2 lines observed with the Spitzer Infrared Spectrograph. The S(0), S(1), and S(2) lines are bright with an extinction-corrected total luminosity of ~2.8 × 10^7 L_☉, or 0.09% of the total-infrared luminosity of NGC 891. The H_2 line ratios are nearly constant along the plane of the galaxy—we do not observe the previously reported strong drop-off in the S(1)/S(0) line intensity ratio in the outer regions of the galaxy, so we find no evidence for the very massive cold CO-free molecular clouds invoked to explain the past observations. The H_2 level excitation temperatures increase monotonically indicating that there is more than one component to the emitting gas. More than 99% of the mass is in the lowest excitation (T_(ex) ~ 125 K) "warm" component. In the inner galaxy, the warm H_2 emitting gas is ~16% of the CO(1-0)-traced cool molecular gas, while in the outer regions the fraction is twice as high. This large mass of warm gas is heated by a combination of the far-UV photons from stars in photodissociation regions (PDRs) and the dissipation of turbulent kinetic energy. Including the observed far-infrared [O I] and [C II] fine-structure line emission and far-infrared continuum emission in a self-consistent manner to constrain the PDR models, we find essentially all of the S(0) and most (70%) of the S(1) line arise from low excitation PDRs, while most (80%) of the S(2) and the remainder of the S(1) line emission arise from low-velocity microturbulent dissipation