SDSS J143030.22-001115.1： A Misclassified Narrow-line Seyfert 1 Galaxy with Flat X-ray Spectrum

We used multi-component profiles to model the Hβ and [OⅢ]λλ4959,5007 lines of SDSS J143030.22-001115.1, a narrow-line Seyfert 1 galaxy (NLS1) in a sample of 150 NLS1 candidates selected from the Sloan Digital Sky Survey (SDSS), Early Data Release (EDR). After subtracting the Hβ contribution from narrow line regions (NLRs), we found that its full width half maximum (FWHM) of broad Hβ line is nearly 2900km s~(-1) , significantly larger than the customarily adopted criterion of 2000 km s~(-1) . With its weak Fe Ⅱ multiples, we believe that SDSS J143030.22-001115.1 should not be classified as a genuine NLS1. When we calculate the virial black hole masses of NLS1s, we should use the Hβ linewidth after subtracting the NLR component.     

The Multi-Wavelength Quasar Survey III. Quasars in Field 836

This is the third paper in a series connected with our Multiwavelength Quasar Survey. The survey is aimed to provide a quasar sample more complete than any previous survey by using a combined selection technique to reduce selection effects. We present the observational results for the X-ray candidates in field f836. We found 15 X-ray AGNs in this field of which eight are new discoveries. The X-ray data and optical spectra of these AGNs are given. We give the X-ray candidate selection criteria, which proved to be highly efficient in isolating X-ray AGNs.     

The Multi-Wavelength Quasar Survey IV. Quasars in the Leo Cluster

We aim to providea quasar sample that is more complete than any previous surveys by using a combined selection technique to reduce the selection effects. Here we present the observational results for the X-ray candidates in the field of the Leo Cluster. We found 33 X-ray AGNs in this field of which 10 are new discoveries. The X-ray data and optical spectra of these AGNs are given. We also study the near-IR properties of the X-ray-selected AGNs by using the data from 2MASS. Most of the AGNs in our sample span the color range 0.0 < B-J < 2.5, 1.0 < J-Ks < 2.0 and 0.5 < H-Ks < 1.2.     

New background quasars in the vicinity of the Andromeda Galaxy discovered with the Guoshoujing Telescope (LAMOST)

Planetary nebulae (PNe) are good tracers of the stellar populations, chem-ical composition and dynamics of their host galaxies. This paper reports the dis-covery of new PNe in the outskirts of the Andromeda Galaxy (M 31) with the Guoshoujing Telescope (GSJT, formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope-LAMOST) during its early commissioning phase. In total, 36 candidates selected from SDSS photometry are confirmed in terms of their PN nature, including 17 new discoveries and another 19 previously known emission line objects. Their positions, spectra, radial velocities and m5007 magnitudes are presented.We discuss the potential for detecting more PNe in M 31 with GSJT's multi-object spectroscopy and the related applications in studies of the dynamics and chemistry of M31 and its assemblage history.     

Discovery of six high-redshift quasars with the Lijiang 2.4 m telescope and the Multiple Mirror Telescope

Quasars with redshifts greater than 4 are rare, and can be used to probe the structure and evolution of the early universe. Here we report the discovery of six new quasars with i-band magnitudes brighter than 19.5 and redshifts between 2.4 and 4.6 from spectroscopy with the Yunnan Faint Object Spectrograph and Camera (YFOSC) at the Lijiang 2.4 m telescope in February, 2012. These quasars are in the list of z > 3.6 quasar candidates selected by using our proposed J K/i Y criterion and the photometric redshift estimations from the SDSS optical and UKIDSS near-IR photometric data. Nine candidates were observed by YFOSC, and five among six new quasars were identified as z > 3.6 quasars. One of the other three objects was identified as a star and the other two were unidentified due to the lower signal-to-noise ratio of their spectra. This is the first time that z > 4 quasars have been discovered using a telescope in China. Thanks to the Chinese Telescope Access Program (TAP), the redshift of 4.6 for one of these quasars was confirmed by the Multiple Mirror Telescope (MMT) Red Channel spectroscopy. The continuum and emission line properties of these six quasars, as well as their central black hole masses and Eddington ratios, were obtained.     

A broad absorption line outflow associated with the broad emission line region in the quasar SDSS J075133.35+134548.3

We report on the discovery of unusual broad absorption lines(BALs)in the bright quasar SDSS J075133.35+134548.3 at z~1,using archival and newly obtained optical and NIR spectroscopic data.The BALs are detected reliably in HeⅠ*λ3889,HeⅠ*λ10830 and tentatively in AlⅢ,MgⅡ.These BALs show complex velocity structures consisting of two major components:a high-velocity component(HV),with a blueshifted velocity range ofΔv_HV~9300--3500 km s^-1,which can be reliably detected in HeⅠ*λ10830,and tentatively in AlⅢand MgⅡ,whereas it is undetectable in HeⅠ*λ3889;and a low-velocity component(LV),withΔv_LV~3500--1800 km s^-1,is only detected in HeⅠ*λ3889 and HeⅠ*λ10830.With the BALs from different ions,the HV outflowing gas can be constrained to have a density of nH~10^10.3-10^11.4 cm^-3,a column density of NH~10²¹ cm^-2and an ionization parameter of U~10^-1.83-10^-1.72;inferring a distance of RHV~0.5 pc from the central continuum source with a monochromatic luminosityλLλ(5100)=7.0×10⁴⁵erg s^-1at 5100 A.This distance is remarkably similar to that of the normal broad line region(BLR)estimated from reverberation experiments,suggesting association of the BLR and the HV BAL outflowing gas.Interestingly,a blueshifted component is also detected in AlⅢand MgⅡbroad emission lines(BELs),and the AlⅢ/MgⅡof such a BEL component can be reproduced by the physical parameters inferred from the HV BAL gas.The LV BAL gas likely has a larger column density,a higher ionization level and hence a smaller distance than the HV BAL gas.Further spectroscopy with a high S/N ratio and broader wavelength coverage is needed to confirm this to shed new light on the possible connection between BALs and BELs.     

Possible evidence of destroying small PAH particles by radiation from AGNs

The issue of destroying small polycyclic aromatic hydrocarbon(PAH) particles by radiation from AGNs is examined through optical narrow-emission line ratios of a sample of type II AGNs. We find that narrow-line ratios [OI]λ6300/Hα and[SII]λ6716, λ6731/Hα have prominent correlations with the PAH 11.3/7.7 ratio in our selected sample of AGNs. Because of the marginal(and in some cases no) dependence of the PAH ratio on the gas metallicity, a possible explanation for the correlations is the destruction of small PAH particles by the hard ionizing field associated with the AGNs.     

Relation between the “Double-Hump” Behavior in the Radio Band and the Broad-Line Luminosity for Blazars

The physics behind the spectral energy distribution (SED) of blazars remains open. We assembled 36 blazars to tackle the factors that control their SED. Now, many blazar spec- tra have the "double hump" feature in the radio and far-IR frequencies. For these a parameter, , is created to characterize the behavior of the SED. We found a significant correlation be- tween the broad-line luminosity (LBLR) and . Because LBLR is an indicator of the accreting power of the source in blazars, we derived a linear correlation, ∝ M˙1/3.18, which suggests that the SED of blazars may depend on the accretion rate, like that of BL Lac objects. We also found a significant correlation between ■ and for a sample of 11 blazars (out of one of 36) with available black hole masses. This implies the Eddington accretion ratio may influence the shape of the SED of blazars.     

The relationship between the radio core dominance parameter and the spectral index in different classes of extragalactic radio sources

Active galactic nuclei(AGNs)have two major classes,namely radio loud AGNs and radio quiet AGNs.A small subset of the radio-loud AGNs is called blazars,which display extreme observational properties,such as rapid variability,high luminosity,high and variable polarization,and superluminal motion.All of those observational properties are probably due to a relativistic beaming effect with the jet pointing close to the line of sight.Observations suggest that the orientation can be expressed by a core-dominance p...     

Chandra archival study of (U)LIRGs with a double nucleus:binary AGNs?

We present our initial results from a study of 14(U)LIRGs with a doublenucleus(z <0.15)and an AGN signature in the Chandra archive.The goals of our study are to search for more possible cases of binary AGNs and to investigate the X-ray properties and energy sources of these energetic objects,a major effort devoted specifically to searching for binary AGNs from(U)LIRGs.Our studies suggest that Mrk 266 might be a new candidate in hosting binary AGNs supported by X-ray observations.Our analysis shows that most(U)LIRGs are essentially weak X-ray sources and are not dominated by AGNs,due to both the lack of Fe K line detections and weak emission in the hard X-ray band.We find evidence for thermal emission with temperature kT～0.7 keV in seven nuclear regions,and this component is possibly associated with the nuclear or circumnuclear starburst.The soft and hard X-ray to far-infrared ratios also suggest that most(U)LIRGs are not energetically dominated by AGNs.Therefore,this study only provides one additional candidate of binary AGNs.We cannot rule out the existence of low luminosity AGNs and thus binary AGNs in all of them,particulaxly,those highly obscured and spatially unresolved systems.Nine of 14(U)LIRGs,including three previously known binary AGNs and a new candidate Mrk 266,clearly have obvious X-ray counterparts to their double optical/near-IR nuclei,whereas only two out of 14 have one obvious X-ray counterpart detected.Additionally,Arp 220 and Mrk 273 are not spatially resolved owing to their small nuclear separations(～1"),and no significant X-ray detection in the most distant source.     

Evidence of the Link between Broad Emission Line Regions and Accretion Disks in Active Galactic Nuclei

1 INTRODUCTION Most bright active galactic nuclei (AGNs) exhibit broad emission lines, with full width at half maximum (FWHM ≥ 103 km s?1) (Peterson et al. 1999). Some type 1 AGNs could have very broad emission lines (FWHM≥ 20 000 km s?1). Type 2 AGNs s…     

Detailed study of B037 based on HST images

B037 is of interest because it is both the most luminous and the most highly reddened cluster known in M31.Deep observations and high spatial resolution images with the Advanced Camera for Surveys on the Hubble Space Telescope(HST) first showed that this cluster is crossed by a dust lane.Photometric data in the F606W and F814W filters obtained in this paper indicate that colors of(F606W-F814W) in the dust lane are redder-0.4 mag than ones in the other regions of B037.The HST images show that this dust lane ...     

A new three-stage evolution model for millimeter to centimeter wavelength outbursts in BL Lacertae

The multi-frequency light curves of BL Lacertae during 1997.5 – 1999.5 have been modeled by four outbursts,each having a 3-stage evolution in the (S m,νm) plane with distinct rising–plateau–decaying phases.It is shown that the observed light curves can be well fitted for the eight frequencies from 350GHz to 4.8GHz.The main characteristics of the model-fitting are: (1) the outbursts are found to have very flat spectra with an optically thin spectral index α (defined as Sν∝ν-α) of about 0.15.This is consisten...     

IRAS F21013-0739: a possible evolutionary successor of an ultraluminous infrared galaxy

We present a stellar populationsynthesis study of a type II luminousinfrared galaxy,IRAS F21013-0739.Optical images show clear characteristics of a merger remnant.The H-band absolute magnitude is MH=-25.1,which is ～ 2 times as luminous as L galaxies.Stellar populations are obtained through the stellar synthesis code starlight.We find that it experienced a recent starburst (SB) phase ～ 100 Myr ago.By reconstructing the ultraviolet-to-optical spectrum,and adopting Calzetti et al.and Leitherer et al.'s extinct...     

A multiwavelength view of the ISM in the merger remnant galaxy Fornax A

We present multi-wavelength imagery of the merger remnant galaxy NGC 1316 with an objective to study the dust content and its association with the other phases of the interstellar medium. Color-index maps as well as extinction maps derived for this galaxy reveal an intricate and complex dust morphology in NGC 1316, i.e. there is a prominent lane in the inner part, while at about 6-7 kpc it apparently takes the form of an arc-like pattern extending along the northeast direction. In addition to this, several other dust clumps and knots are also evident in this galaxy. The dust emission mapped using Spitzer data at 8 μm indicates even more complex morphological structures of the dust in NGC 1316. The extinction curve derived over the optical to near-IR bands closely follows the standard Galactic curve, suggesting similar properties of the dust grains. The dust content of NGC 1316, estimated from optical extinction, is ～ 2.13 105M⊙ . This is a lower limit compared to that estimated using the IRAS flux densities of ～5.17×106M⊙ and the flux densities at 24, 70 and 160 μm from MIPS ～3.2×107M⊙ . High resolution Chandra observations of this merger remnant system have provided an unprecedented view of the complex nature exhibited by the distribution of hot gas in NGC 1316, which closely matches the morphology of ionized gas and to some extent also the dust. X-ray color-color plots for the resolved sources within the optical D 25 extent of NGC 1316 have enabled us to separate them into different classes.     

New planetary nebulae in the outskirts of the Andromeda Galaxy discovered with the Guoshoujing Telescope (LAMOST)

Planetary nebulae (PNe) are good tracers of the stellar populations, chemical composition and dynamics of their host galaxies. This paper reports the discovery of new PNe in the outskirts of the Andromeda Galaxy (M 31) with the Guoshoujing Telescope (GSJT, formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope-LAMOST) during its early commissioning phase. In total, 36 candidates selected from SDSS photometry are confirmed in terms of their PN nature, including 17 new discoveries and an...     

Kinematics and stellar population properties of the Andromeda galaxy by using the spectroscopic observations of the Guoshoujing Telescope

The Andromeda galaxy was observed by the Guoshoujing Telescope (formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope — LAMOST),during the 2009 commissioning phase.Due to the absence of standard stars for flux calibration,we use the photometric data of 15 intermediate bands in the Beijing-Arizona-Taipei-Connecticut (BATC) survey to calibrate the spectra.In total,59 spectra located in the bulge and disk of the galaxy are obtained.Kinematic and stellar population properties of the stell...     

Spectroscopic and photometric observations of unidentified ultraviolet variable objects in the GUVV-2 Catalog

An NUV-optical diagram composed from sources from the second Galaxy Evolution Explorer(GALEX) Ultraviolet Variability(GUVV-2) Catalog provides us with a method to tentatively classify the unknown GUVV-2 sources by their NUV-optical magnitudes.For the purpose of testing the correctness and generality of the method,we carry out a program on the spectroscopic observations of the unidentified GUVV-2 sources.The spectroscopic identification of these 37 sources are 19 type-A to-F stars,10 type-G to-K stars and 7 ...