Supermassive Primordial Black Holes for Nano-Hertz Gravitational Waves and High-redshift JWST Galaxies

Recently,observational hints for supermassive black holes have been accumulating,prompting the question:Can primordial black holes(PBHs)be supermassive,particularly with masses M■10^(9)M_(⊙)?A supercritical bubble,containing an inflating baby universe,that nucleated during inflation can evolve into a PBH in our observable universe.We find that when the inflaton slowly transitions past a neighboring vacuum,the nucleation rate of supercritical bubbles inevitably peaks,leading to a mass distribution of multiverse PBHs with a peak mass up to M■10^(11)M_(⊙).Thus,our mechanism naturally provides a primordial origin for supermassive black holes.

Similarity of jet radiation between flat spectrum radio quasars and GeV narrow-line Seyfert 1 galaxies: a universal δ-Lc correlation

By modeling the broadband spectral energy distributions （SEDs） of a typical flat spectrum radio quasar （FSRQ, 3C 279） and two GeV narrow-line Seyfert 1 galaxies （NLSls, PMN J0948＋0022 and 1H 0323＋342） in different flux stages with one-zone leptonic models, we find a universal correlation between their Doppler factors （δ） and peak luminosities （Lc） of external Compton scattering bumps. Compiling a combined sample of FSRQs and GeV NLSls, it is found that both FSRQs and GeV NLSls in different stages and in different sources follow the same δ-Lc correlation well. This indicates that the variations of observed luminosities may be essentially due to the Doppler boosting effect. The universal δ-Lo relation between FSRQs and GeV NLS 1 s in different stages may be further evidence that the particle acceleration and radiation mechanisms for the two kinds of sources are similar. In addition, by replacing Lc with the observed luminosity in the Fermi/LAT band （LLAT）, this correlation holds and it may serve as an empirical indicator of δ. We estimate the δ values with LLAT for 484 FSRQs in the Fermi/LAT Catalog and they range from 3 to 41, with a median of 16, which are statistically consistent with the values derived by other methods.

The Difference between the α-disks of Seyfert 1 Galaxies and Quasars

In a previous paper, it was suggested that contamination of the nuclear luminosity by the host galaxy plays an important role in determining the parameters of the standard a disk of AGNs. Using the nuclear absolute B band magnitude instead of the total absolute B band magnitude, we have recalculated the central black hole masses, accretion rates and disk inclinations for 20 Seyfert 1 galaxies and 17 Palomar-Green (PG) quasars. It is found that a small value of a is needed for the Seyfert 1 galaxies than for the PG quasars. This difference in a possibly leads to the different properties of Seyfert 1 galaxies and quasars. Furthermore, we find most of the objects in this sample are not accreting at super-Eddington rates if we adopt the nuclear optical luminosity in our calculation.

Formation and Evolution of Galaxies and Its Black Holes and Quasars

Galaxy formation and evolution is one of the most active research areas in astrophysics,so many people have studied this area.But since they didn’t understand thoroughly the evolution law from satellite to planet then to star,their theories are very weak.In their theories,they proposed that large gas clouds collapsing to form a galaxy or more recently that matter started out in smaller clumps merged to form galaxy,which is incredible.Hence,the author of this paper,through studying the formation and orbit-variation of satellites,planets and stars,has put forward a new theory of galaxy formation and evolution,therefore revealing the hierarchical structure of galaxies and the formation and evolution of black holes and quasars.

Merging History of Massive Galaxies at 3

The observational data of high redshift galaxies become increasingly abundant,especially since the operation of the James Webb Space Telescope,which allows us to verify and optimize the galaxy formation model at high redshifts.In this work,we investigate the merging history of massive galaxies at 3<z<6 using a well-developed semi-analytic galaxy formation catalog.We find that the major merger rate increases with redshift up to 3 and then flattens.The fraction of wet mergers,during which the sum of the cold gas mass is higher than the sum of the stellar mass in two merging galaxies,also increases from~34%at z=0 to 96%at z=3.Interestingly,almost all major mergers are wet at z>3.This can be attributed to the high fraction(>50%)of cold gas at z>3.In addition,we study some special systems of massive merging galaxies at 3<z<6,including the massive gas-rich major merging systems and extreme dense proto-clusters,and investigate the supermassive black hole-dark matter halo mass relation and dual active galactic nuclei.We find that the galaxy formation model reproduces the incidence of those observed massive galaxies,but fails to reproduce the relation between the supermassive black hole mass and the dark matter halo mass at z~6.The latter requires more careful estimates of the supermassive black hole masses observationally.Otherwise,it could suggest modifications of the modeling of the supermassive black hole growth at high redshifts.

Study of Central Intensity Ratio of Seyfert Galaxies in Nearby Universe

We use the recently discovered simple photometric parameter Central Intensity Ratio(CIR)determined for a sample of 57 nearby(z<0.02)Seyfert galaxies to explore the central features of galaxies and their possible connection with galaxy evolution.The sample of galaxies shows strong anti-correlation between CIR and mass of their central supermassive black holes(SMBHs).The SMBH masses of ellipticals are systematically higher for a given CIR value than those for lenticulars and spirals in the sample.However,the correlation between CIR and central velocity dispersion is weak.CIR appears less influenced by the excess flux produced by the central engine in these galaxies,when compared to spectroscopic parameters like velocity dispersion and OⅣflux,and proves to be a fast and reliable tool for estimating central SMBH mass.

The AGN Feedback in Compact Galaxies:On the Impact of a More Massive Central Black Hole

We conduct high-resolution hydrodynamical simulations using the MACER framework to investigate the interplay between the interstellar medium,active galactic nuclei(AGN)feedback and black hole(BH)feeding in a massive compact galaxy,with an emphasis on the impact of different central BH masses.We find that with a more massive central BH,high-speed outflows are more prominent,and the gas fraction in the compact galaxy is reduced.Due to the lower gas density and higher gas temperature,the compact galaxy with a more massive BH(MAS galaxy)remains predominantly single-phase with the cooling time t_(cool)■100t_(ff).In contrast,the compact galaxy with the reference BH mass(REF galaxy)maintains a higher gas fraction with a shorter cooling time,slightly more multiphase gas and less prominent outflows.We further demonstrate that the difference in gas thermal states and kinematics is caused by the stronger AGN feedback in the compact galaxy with a more massive BH,where the AGN wind power is twice as much as that with the reference BH.Since the AGN feedback efficiently suppresses the inflow rate and the BH feeding rate,the BH mass growth is significant in neither the compact galaxy with the reference BH nor that with the more massive BH,only by 24%and 11%of the initial BH mass,respectively,over the entire evolution time of 10 Gyr.We thus posit that without ex situ mass supply from mergers,the massive BHs in compact galaxies cannot grow significantly via gas accretion during the late phase,but might have already formed by the end of the rapid early phase of galaxy formation.

First Neutral Atomic Hydrogen Images of Quasar Host Galaxies

Violent galactic encounters or mergers are the leading contenders for triggering luminous quasar activity at low redshifts: such interactions can lead to the concentration of gas in the host galactic nucleus, thus fueling the suspected central superrmassive black hole. Although optical images show a number of violently interacting systems, in many cases the evidence for such interactions is only circumstantial (e.g., asymmetric optical morphologies, projected nearby companion galaxies) or not at all apparent. Here we image quasar host galaxies for the first time in the redshifted 21 cm line emission of neutral atomic hydrogen (HI) gas, which in nearby galaxies has proven to be a particularly sensitive as well as enduring tracer of tidal interactions. The three quasars studied have different optical environments normally seen around low reshift quasars, ranging from a perhaps mildly interacting system to a relatively undisturbed host with a projected neighbouring galaxy to an isolated and apparently serene host galaxy. By contrast with their optical appearences, all three quasar host galaxies exhibit ongoing or remnant tidal HI disruptions tracing galactic encounters or mergers. These observations provide a better understanding of the likely stage of their interaction.

Eight new quasars discovered by the Guoshoujing Telescope (LAMOST) in one extragalactic field

We report the discovery of eight new quasars in one extragalactic field （a five-degree field centered at RA=08^h58^m08.2^s, Dec=01°32′29.7″） with the Guoshoujing Telescope （LAMOST） commissioning observations made on 2009 December 18. These quasars, with i magnitudes from 16.44 to 19.34 and redshifts from 0.898 to 2.773, were not identified in the SDSS spectroscopic survey, though six of them with redshifts less than 2.5 were selected as quasar targets in SDSS. Except for one source without near-IR Y-band data, seven of these eight new quasars satisfy a newly proposed quasar selection criterion involving both near-IR and optical colors. Two of them were found in the ＇redshift desert＇ for quasars （z from 2.2 to 3）, indicating that the new criterion is efficient for uncovering missing quasars with similar optical colors to stars. Although LAMOST encountered some problems during the commissioning observations, we were still able to identify 38 other known SDSS quasars in this field, with i magnitudes from 16.24 to 19.10 and redshifts from 0.297 to 4.512. Our identifications imply that a substantial fraction of quasars may be miss- ing in previous quasar surveys. The implication of our results to the future LAMOST quasar survey is discussed.

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

We present preliminary analyses of spectra of quasar candidates in two Guoshoujing Telescope （GSJT, formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope - LAMOST） test fields near M 31 where one is close to the optical center of the disk and the other is towards the northeastern outskirts of the halo, obtained during the early stage of the GSJT commissioning in the last season of 2009. Both fields contain background low-redshift quasar candidates selected from the SDSS photometry. In total, 14 new quasars with redshifts up to 2 and i magnitudes between 16.7 and 19.2, are discovered, including 7 within the 2.5° central region of M 31. We briefly discuss the potential applications of these newly discovered bright quasars.

Comparisons of Jet Properties between GeV Radio Galaxies and Blazars

We compile a sample of spectral energy distributions （SEDs） of 12 GeV radio galaxies （RGs）, including eight FR I RGs and four FR II RGs. These SEDs can be represented with the one-zone leptonic model. No significant unification, as expected in the unification model, is found for the derived jet parameters between FR I RGs and BL Lacertae objects （BL Lacs） and between FR II RGs and flat spectrum radio quasars （FSRQs）. However, on average FR I RGs have a larger ＇Tb （break Lorentz factor of electrons） and lower B （magnetic field strength） than FR II RGs, analogous to the differences be- tween BL Lacs and FSRQs. The derived Doppler factors （~） of RGs are on average smaller than those of blazars, which is consistent with the unification model such that RGs are the misaligned parent pop- ulations of blazars with smaller tS. On the basis of jet parameters from SED fits, we calculate their jet powers and the powers carded by each component, and compare their jet compositions and radiation efficiencies with blazars. Most of the RG jets may be dominated by particles, like BL Lacs, not FSRQs. However, the jets of RGs with higher radiation efficiencies tend to have higher jet magnetization. A strong anticorrelation between synchrotron peak frequency and jet power is observed for GeV RGs and blazars in both the observer and co-moving frames, indicating that the ＂sequence＂ behavior among blazars, together with the GeV RGs, may be intrinsically dominated by jet power.

GeneticKNN:a weighted KNN approach supported by genetic algorithm for photometric redshift estimation of quasars

We combine K-nearest neighbors(KNN)with a genetic algorithm(GA)for photometric redshift estimation of quasars,short for GeneticKNN,which is a weighted KNN approach supported by a GA.This approach has two improvements compared to KNN:one is the feature weighted by GA;the other is that the predicted redshift is not the redshift average of K neighbors but the weighted average of median and mean of redshifts for K neighbors,i.e.p×zmedian+(1-p)×zmean.Based on the SDSS and SDSS-WISE quasar samples,we explore the performance of GeneticKNN for photometric redshift estimation,comparing with the other six traditional machine learning methods,i.e.the least absolute shrinkage and selection operator(LASSO),support vector regression(SVR),multi-layer perceptrons(MLP),XGBoost,KNN and random forest.KNN and random forest show their superiority.Considering the easy implementation of KNN,we make improvement on KNN as GeneticKNN and apply GeneticKNN on photometric redshift estimation of quasars.Finally the performance of GeneticKNN is better than that of LASSO,SVR,MLP,XGBoost,KNN and random forest for all cases.Moreover the accuracy is better with the additional WISE magnitudes for the same method.

Luminosity Function of the Cluster of Galaxies Abell 566

We investigate the Luminosity Function （LF） of the cluster of galaxies Abell 566. The photometric data of 15 intermediate-bands are obtained from the Beijing-Arizona- Taiwan-Connecticut （BATC） photometric sky survey. For each of the 15 wavebands, the LF of cluster galaxies is well modelled by the Schechter function, with characteristic luminosities from -18.0 to -21.9 magnitude, from the α- to the p-band. Morphological dependence of the LF is investigated by separating the cluster members into ＇red＇ and ＇blue＇ subsamples. It is clear that late type galaxies have a steeper shape of LF than the early type galaxies. We also divided the sample galaxies by their local environment. It was found that galaxies in the sparser region have steeper shape of LF than galaxies in the denser region. Combining the results of morphological and environmental dependence of LFs, we show that Abell 566 is a well relaxed cluster with positive evidence of galaxy interaction and merger, and excess number of bright early type galaxies located in its denser region.

Radio Luminosity,Black Hole Mass and Eddington Ratio for Quasars from the Sloan Digital Sky Survey

We investigate the MBH-σ＊ relation for radio-loud quasars with redshifl z 〈 0.83 in Data Release 3 of the Sloan Digital Sky Survey （SDSS）. The sample consists of 3772 quasars with better models of the H/4 and [O Ⅲ] lines and available radio luminosity, including 306 radio-loud quasars, 3466 radio-quiet quasars with measured radio luminosity or upper-limit of radio luminosity （181 radio-quiet quasars with measured radio luminosity）. The virial supermassive black hole mass （MBH） is calculated from the broad Hβline, and the host stellar velocity dispersion （σ＊） is traced by the core [O Ⅲ] gaseous velocity dispersion. The radio luminosity and radio loudness are derived from the FIRST catalog. Our results are as follows： （1） For radio-quiet quasars, we confirm that there is no obvious deviation from the MBH-σ＊ relation defined for inactive galaxies when the uncertainties in ~IBH and the luminosity bias are concerned. （2） We find that the radio-loud quasars deviate more from the MBH-σ＊ relation than do the radio-quiet quasars. This deviation is only partly due to a possible cosmological evolution of the MBH-σ＊ relation and the luminosity bias. （3） The radio luminosity is proportional to MBH1.28＋0.23-0.16（LBol/LEdd） ^1.29＋0.31-0.24 for radio-quiet quasars and to -MBH3.10＋0.60-0.70（LBol/LEdd）^4.18＋1.40-1.10 - for radio-loud quasars. The weaker dependence of the radio luminosity on the mass and the Eddington ratio for radio-loud quasars shows that other physical effects would account for their radio luminosities, such as the spin of the black hole.

A new estimation of manganese distribution for local dwarf spheroidal galaxies

The distribution of abundance for iron-peak elements in dwarf spheroidal galaxies （dSphs） is important for galaxy evolution and supernova （SN） nucleosynthesis. Nowadays, manganese （Mn） is one of the most observed iron-peak elements in local dSphs. Studies of its distributions allow us to derive and understand the evolution history of these dSphs. We improve a phenomenological model by a two-curve model including a new initial condition, that includes detailed calculations of SN explosion rates and yields. We compare the results with the observed Mn distribution data for three dSphs： Fornax, Sculpture and Sextans. We find that the model can describe the observed Fe and Mn distributions well simultaneously for the three dSphs. The results also indicate that the initial conditions should be determined by the low metallicity sam- ples in the beginning time of the galaxies and the previous assumption of metellicity-dependant Mn yield of SNIa is not needed when a wide mass range of core-collapse SNe is included. Our method is applicable to the chemical evolution of other iron-peak elements in dSphs and can be modified to provide more detailed processes for the evolution of dSphs.

Are Seyfert 2 Galaxies without Polarized Broad Emission Lines More Obscured?

New XMM-Newton data of seven Seyfert 2 galaxies with optical spectropolarimetric observations are presented. An analysis of the 0.5 - 10 keV spectra shows that four Seyfert 2 galaxies with polarized broad lines （PBLs） are absorbed by NH 〈 1024 cm^-2, while two of three Seyfert 2 galaxies without PBLs show evidence of Compton-thick obscuration, supporting the conclusion that Seyfert 2 galaxies without PBLs are more obscured than those with PBLs, Adding the measured obscuration indicators （NH, T ratio, and Fe Kα line EW） of six luminous AGNs to our previous sample improves the significance level of the difference in absorption from 92.3% to 96.3% for NH, 99.1% to 99.4% for T ratio, and 95.3% to 97.4% for Fe Kα line EW. The present results support and enhance the suggestions that the absence of PBLs in Seyfert 2 galaxies can be explained by larger viewing angles of the line of sight to the putative dusty toms, which leads to the obscuration of the broad-line scattering screen, as expected in the unification model.

Lensing clusters of galaxies in the SDSS-Ⅲ

We identify new strong lensing clusters of galaxies from the Sloan Digital Sky Survey Ⅲ （SDSS DR8） by visually inspecting color images of a large sample of clusters of galaxies. We find 68 new clusters showing giant arcs in addition to 30 known lensing systems. Among 68 cases, 13 clusters are ＂almost certain＂ lensing systems with tangential giant arcs, 22 clusters are ＂probable＂ and 31 clusters are ＂pos- sible＂ lensing systems. We also find two exotic systems with blue rings. The giant arcs have angular separations of 2.0jj - 25.7j~ from the bright central galaxies. We note that the rich clusters are more likely to be lensing systems and the separations between the arcs and the central galaxies increase with cluster richness.

Hydrodynamical simulations of the triggering of nuclear activities by minor mergers of galaxies

Major mergers of galaxies are considered to be an efficient way to trigger Active Galactic Nuclei and are thought to be responsible for the phenomenon of quasars. This has however recently been challenged by observations of a large number of low luminosity Active Galactic Nuclei at low redshift(z■1) without obvious major merger signatures. Minor mergers are frequently proposed to explain the existence of these Active Galactic Nuclei. In this paper, we perform nine high resolution hydrodynamical simulations of minor galaxy mergers, and investigate whether nuclear activities can be efficiently triggered by minor mergers, by setting various properties for the progenitor galaxies of those mergers. We find that minor galaxy mergers can activate the massive black hole in the primary galaxy with an Eddington ratio of f Edd > 0.01 and> 0.05(or a bolometric luminosity > 10^43 and > 10^44 erg s^-1) with a duration of 2.71 and 0.49 Gyr(or 2.69 and 0.19 Gyr), respectively. The nuclear activity of the primary galaxy strongly depends on the nucleus separation, such that the nucleus is more active as the two nuclei approach each other. Dual Active Galactic Nuclei systems can still possibly be formed by minor mergers of galaxies, though the time duration for dual Active Galactic Nuclei is only ~ 0.011 Gyr and ~ 0.017 Gyr with Eddington ratio of f Edd > 0.05 and bolometric luminosity > 10^44 erg s^-1. This time period is typically shorter than that of dual Active Galactic Nuclei induced by major galaxy mergers.

Photometric redshift estimation for quasars by integration of KNN and SVM

The massive photometric data collected from multiple large-scale sky surveys offer significant opportunities for measuring distances of celestial objects by photometric redshifts. However, catastrophic failure is an unsolved problem with a long history and it still exists in the current photometric redshift estimation approaches （such as the k-nearest neighbor （KNN） algorithm）. In this paper, we propose a novel two-stage approach by integration of KNN and support vector machine （SVM） methods together. In the first stage, we apply the KNN algorithm to photometric data and estimate their corresponding Zphot. Our analysis has found two dense regions with catastrophic failure, one in the range of Zphot E [0.3, 1.2] and the other in the range of Zphot E [1.2, 2.1]. In the second stage, we map the photometric input pattern of points falling into the two ranges from their original attribute space into a high dimensional feature space by using a Gaussian kernel function from an SVM. In the high dimensional feature space, many outliers resulting from catastrophic failure by simple Euclidean distance computation in KNN can be identified by a classification hyperplane of SVM and can be further corrected. Experimental results based on the Sloan Digital Sky Survey （SDSS） quasar data show that the two-stage fusion approach can significantly mitigate catastrophic failure and improve the estimation accuracy of photometric redshifts of quasars. The percents in different /△z/ ranges and root mean square （rms） error by the integrated method are 83.47%, 89.83%, 90.90% and 0.192, respectively, compared to the results by KNN （71.96%, 83.78%, 89.73% and 0.204）.

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.