Showing papers in "Astrophysics and Space Science in 2009"

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

Abstract: We review and discuss horizontal branch (HB) stars in a broad astrophysical context, including both variable and non-variable stars A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics We show that the Oosterhoff dichotomy and the distribution of globular clusters in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC—an argument which, due to its strong reliance on the ancient RR Lyrae stars, is essentially independent of the chemical evolution of these systems after the very earliest epochs in the Galaxy’s history Convenient analytical fits to isochrones in the HB type–[Fe/H] plane are also provided In this sense, a rediscussion of the second-parameter problem is also presented, focusing on the cases of NGC 288/NGC 362, M13/M3, the extreme outer-halo globular clusters with predominantly red HBs, and the metal-rich globular clusters NGC 6388 and NGC 6441 The recently revived possibility that the helium abundance may play an important role as a second parameter is also addressed, and possible constraints on this scenario discussed We critically discuss the possibility that the observed properties of HB stars in NGC 6388 and NGC 6441 might be accounted for if these clusters possess a relatively minor population of helium-enriched stars A technique is proposed to estimate the HB types of extragalactic globular clusters on the basis of integrated far-UV photometry The importance of bright type II Cepheids as tracers of faint blue HB stars in distant systems is also emphasized The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyr, is also revisited Taking into due account the evolutionary status of RR Lyr, the derived relation implies a true distance modulus to the LMC of (m–M)0=1844±011 Techniques providing discrepant slopes and zero points for the MV(RRL)–[Fe/H] relation are briefly discussed We provide a convenient analytical fit to theoretical model predictions for the period change rates of RR Lyrae stars in globular clusters, and compare the model results with the available data Finally, the conductive opacities used in evolutionary calculations of low-mass stars are also investigated

The trouble with the Local Bubble

Abstract: The model of a Local Hot Bubble has been widely accepted as providing a framework that can explain the ubiq- uitous presence of the soft X-ray background diffuse emis- sion. We summarize the current knowledge on this local in- terstellar region, paying particular reference to observations that sample emission from the presumed local million de- gree K hot plasma. However, we have listed numerous ob- servations that are seemingly in conflict with the concept of a hot Local Bubble. In particular, the discovery of solar wind charge exchange that can generate an appreciable soft X-ray background signal within the heliosphere, has led to a re- assessment of the generally accepted model that requires a hot local plasma. In order to explain the majority of observations of the local plasma, we forward two new speculative models that describe the physical state of the local interstellar gas. One possible scenario is similar to the present widely accepted model of the Local Hot Bubble, except that it accounts for only 50% of the soft X-ray emission currently detected in the galactic plane, has a lower thermal pressure than pre- viously thought, and its hot plasma is not as hot as previ- ously believed. Although such a model can solve several difficulties with the traditional hot Local Bubble model, a heating mechanism for the dimmer and cooler gas remains to be found. The second possible explanation is that of the 'Hot Top' model, in which the Local Cavity is an old su-

The effect of the dynamical state of clusters on gas expulsion and infant mortality

Abstract: The star-formation efficiency (SFE) of a star cluster is thought to be the critical factor in determining if the cluster can survive for a significant (>50 Myr) time. There is an often quoted critical SFE of ∼30% for a cluster to survive gas expulsion. I reiterate that the SFE is not the critical factor; rather, it is the dynamical state of the stars (as measured by their virial ratio) immediately before gas expulsion. If the stars in a star cluster are born in an (even slightly) cold dynamical state, then the survivability of a cluster can be greatly increased.

WSO-UV—ultraviolet mission for the next decade

Abstract: The World Space Observatory UltraViolet (WSO-UV) is an international space mission devoted to UV spectroscopy and imaging. The observatory includes a 170 cm aperture telescope capable of high-resolution and long slit low-resolution spectroscopy, and deep UV and optical imaging. The observatory is designed for observations in the ultraviolet domain where most of astrophysical processes can be efficiently studied with unprecedented capability.

The Ultraviolet sky surveys: filling the gap in our view of the Universe

Abstract: The GALEX mission is performing imaging and spectroscopic surveys of the sky at Ultraviolet wavelengths, and providing unprecedented sky maps in two UV bands, far-UV and near-UV, and catalogs of UV sources. I will describe the major surveys accomplished so far, and results in investigating the nature of the UV sources. The UV surveys, linked to a multi-wavelength archive, offer great sensitivity to detect and characterize several classes of astrophysical objects, such as low-redshift QSOs, star-forming galaxies, and white dwarfs (WD) in the Milky Way. Efforts towards obtaining a significant census of WDs from GALEX imaging data are described in particular. A dedicated, deep survey of nearby galaxies provides a snapshot of their recent star formation, shedding new light on the process of star formation and its modalities in different environments and conditions. Deep GALEX data revealed young stellar populations in extreme outskirts of spiral galaxies, previously thought to be stable against star formation given their low density. UV measurements for millions of nearby and distant galaxies map the history and probe the causes of star formation in the Universe over the redshift range z=0–2.

Classification of BeppoSAX's gamma-ray bursts

Abstract: The BeppoSAX Catalog has been very recently published. In this paper we analyze—using the Maximum Likelihood (ML) method—the duration distribution of the 1003 GRBs listed in the catalog with duration. The ML method can identify the long and the intermediate duration groups. The short population of the bursts is identified only at a 96% significance level. MC simulation has been also applied and gives a similar significance level; 95%. However, the existence of the short bursts is not a scientific question after the Compton Gamma-Ray Observatory’s observation. Our minor result is this well-known fact that in the BeppoSAX data the short bursts are under-represented, mainly caused by the different triggering system. Our major result is the identification of the intermediate group in the BeppoSAX data. Therefore, four different satellites (CGRO, Swift, RHESSI and BeppoSAX) observed the intermediate type Gamma-Ray Burst.

Organic matter in space: from star dust to the Solar System

Abstract: Organic compounds of high degree of complexity are now known to be widespread in the Universe, ranging from objects in our Solar System to distant galaxies. Through the techniques of millimeter-wave spectroscopy, over 140 molecules have been identified through their rotational transitions. Space infrared spectroscopy has detected the stretching and bending modes of compounds with aromatic and aliphatic structures. Analyses of samples of meteorites, comets, asteroids, and interplanetary dust also revealed a rich content of organic substances, some of which could be of extra-solar origin. We review the current state of understanding of the origin, evolution, nature, and distribution of organic matter in space. Also discussed are a number of unexplained astronomical phenomena whose origins could be traced to organic carriers.

Galactic dynamos and galactic winds

Abstract: Spiral galaxies host dynamically important magnetic fields which can affect gas flows in the disks and halos. Total magnetic fields in spiral galaxies are strongest (up to 30 μG) in the spiral arms where they are mostly turbulent or tangled. Polarized synchrotron emission shows that the resolved regular fields are generally strongest in the interarm regions (up to 15 μG). Faraday rotation measures of radio polarization vectors in the disks of several spiral galaxies reveal large-scale patterns which are signatures of coherent fields generated by a mean-field dynamo. Magnetic fields are also observed in radio halos around edge-on galaxies at heights of a few kpc above the disk. Cosmic-ray driven galactic winds transport gas and magnetic fields from the disk into the halo. The halo scale height and the electron lifetime allow to estimate the wind speed. The magnetic energy density is larger than the thermal energy density, but smaller than the kinetic energy density of the outflow. There is no observation yet of a halo with a large-scale coherent dynamo pattern. A global wind outflow may prevent the operation of a dynamo in the halo. Halo regions with high degrees of radio polarization at very large distances from the disk are excellent tracers of interaction between galaxies or ram pressure of the intergalactic medium. The observed extent of radio halos is limited by energy losses of the cosmic-ray electrons. Future low-frequency radio telescopes like LOFAR and the SKA will allow to trace halo outflows and their interaction with the intergalactic medium to much larger distances.

Collisionless interaction of an energetic laser produced plasma with a large magnetoplasma

Abstract: We have commissioned a high-energy glass-laser at the Large Plasma Device (LAPD) to study the interaction of a dense laser-produced plasma with a large (17 m) magnetized plasma. First experiments with an energy of the laser blow-off an order of magnitude higher than previous work (Gekelman et al. in J. Geophys. Res. 108(A7):1281, 2003) produced large amplitude Alfven waves (δ B ⊥ /B 0≈15%). We will discuss the potential of this facility for collisionless laboratory astrophysics experiments.

The cosmic origins spectrograph: capabilities and prelaunch performance

Abstract: The Cosmic Origins Spectrograph (COS) is an ultraviolet spectrograph scheduled for installation in the Hubble Space Telescope (HST) during HST Servicing Mission 4, currently planned to occur in August 2008. COS was designed to maximize sensitivity to faint point sources, and will provide limiting sensitivities at moderate spectral resolutions (R∼20,000) that are a factor of 2 to >10 times better than those provided by previous ultraviolet spectrographs on HST. Here, we present an overview of the some of the science areas that will be addressed by COS observations and provide a summary of the capabilities of COS and the expected on-orbit performance.

Bulk viscous string cosmological models with electromagnetic field

Abstract: LRS Bianchi type-I string cosmological models are studied in the frame work of general relativity when the source for the energy momentum tensor is a bulk viscous stiff fluid containing one dimensional strings embedded in electromagnetic field. The bulk viscosity is assumed to be inversely proportional to the scalar expansion. The physical and kinematical properties of the models are discussed. The effects of Viscosity and electromagnetic field on the physical and kinematical properties are also investigated.

The role of high-pressure experiments on determining super-Earth properties

Abstract: Super-Earths are the newest class of extra-solar planets with a mass range between about 1–10M ⊕ . With their large masses, they experience very large internal pressures. The central pressure scales proportionately with mass, reaching values that require us to extend our understanding of rock and H2O behavior to such extreme conditions. Pressure also constrains the power law relationship between mass and radius of solid planets R∼M β . The value for the exponent is 0.262≤β≤0.274 as constrained by the different internal structure models for super-Earths, while it is 0.3 for planets between 5–50% the mass of Earth. Despite uncertainties in planetary composition, temperature structure and equation of state, the mass-radius relationship is robust, and thus, useful for inferring the expected signal in transit searches. In the next few years many super-Earths will be discovered and their masses and radii will be known with some uncertainty. Even without errors in both the data and structure models, a large number of compositions can fit the same average density. However, the follow-up observations with space telescopes will yield very precise radius measurements and even probe the atmospheres of super-Earths. This radius uncertainty will then be comparable to the current error derived from the equation of state used by the structure models. Thus, there is a need for accurate equations of state of solid planetary materials. Furthermore, information on the structure, such as the size and state of the core, crucially depends on the exact behavior of super-Earth materials (i.e. silicates, iron, iron alloy and ices) at high pressures and temperatures. In addition, information about the atmospheric composition of these planets may prove useful in constraining their interiors. Ultimately any inference on the structure of super-Earths, including information from atmospheres, depends on the precision of interior models, which in turn require accurate equations of state.

Classification of and recent research involving radiative shocks

Abstract: Radiative shocks (RS) occur in astrophysical systems and in high-energy density laboratory experiments. Aided by three dimensionless parameters, we propose a classification of RS into four types, integrating previous work that has focused independently on optical depth and on Mach number. Specific terms, such as a cooling function, a radiative flux, or radiative energy and pressure must be added to the Euler equations in order to model these various kinds of shocks. We examine how these terms correspond to the radiative classification regimes. In astrophysics, observed RS arise generally in optically thin material. Thus, radiation escapes without interaction with the surrounding gas, except perhaps to ionize it, and the energy loss in such shocks can be modeled by a cooling function Λ. In this case only the post-shock region is structured by the radiation cooling. We found the analytical solution for hydrodynamic equations including Λ∝ ρ e P ζ x θ for arbitrary values of e, ζ, θ. This is a completely new result. An application of this calculation for the accretion shock in cataclysmic variables of polar type is given in astrophysical terms. We also draw a parallel between RS experiments performed using the LULI2000 laser facility, in France and the Omega laser Facility, in USA. RS developed in these laboratories are more or less optically thick. These high-Mach number RS present a radiative precursor.

Periodic orbits in the photogravitational restricted problem with the smaller primary an oblate body

Abstract: In this paper, we have studied periodic orbits generated by Lagrangian solutions of the restricted three body problem when more massive body is a source of radiation and the smaller primary is an oblate body. We have determined periodic orbits for fixed values of μ, σ and different values of p and h (μ mass ratio of the two primaries, σ oblate parameter, p radiation parameter and h energy constant). These orbits have been determined by giving displacements along the tangent and normal to the mobile co-ordinates as defined by Karimov and Sokolsky (in Celest. Mech. 46:335, 1989). These orbits have been drawn by using the predictor-corrector method. We have also studied the effect of radiation pressure on the periodic orbits by taking some fixed values of μ and σ.

Formation of episodic magnetically driven radiatively cooled plasma jets in the laboratory

Abstract: We report on experiments in which magnetically driven radiatively cooled plasma jets were produced by a 1 MA, 250 ns current pulse on the MAGPIE pulsed power facility. The jets were driven by the pressure of a toroidal magnetic field in a “magnetic tower” jet configuration. This scenario is characterized by the formation of a magnetically collimated plasma jet on the axis of a magnetic “bubble”, confined by the ambient medium. The use of a radial metallic foil instead of the radial wire arrays employed in our previous work allows for the generation of episodic magnetic tower outflows which emerge periodically on timescales of ∼30 ns. The subsequent magnetic bubbles propagate with velocities reaching ∼300 km/s and interact with previous eruptions leading to the formation of shocks.

Periodic orbits generated by Lagrangian solutions of the restricted three body problem when one of the primaries is an oblate body

Abstract: We have studied periodic orbits generated by Lagrangian solutions of the restricted three body problem when one of the primaries is an oblate body. We have determined the periodic orbits for different values of μ, h and A (h is energy constant, μ is mass ratio of the two primaries and A is an oblateness factor). These orbits have been determined by giving displacements along the tangent and normal to the mobile coordinates as defined by Karimov and Sokolsky (Celest. Mech. 46:335, 1989). These orbits have been drawn by using the predictor-corrector method. We have also studied the effect of oblateness by taking some fixed values of μ, A and h. As starters for our method, we use some known periodic orbits in the classical restricted three body problem.

Axially symmetric string cosmological models in Brans-Dicke theory of gravitation

Abstract: Axially symmetric string cosmological models are obtained in a scalar- tensor theory of gravitation proposed by Brans and Dicke (Phys. Rev. 124:925, 1961). Some physical and geometrical properties of the models are also discussed. The models are anisotropic and free from singularities.

Scaling laws for radiating fluids: the pillar of laboratory astrophysics

Abstract: In this paper, we derive the scaling laws for different radiating fluids. The studied regimes are relevant for both laboratory astrophysics and High Energy Density Physics. Using Lie groups theory, we obtain scaling laws, the similarity properties and the number of free parameters to rescale experiments.

The Baltimore and Utrecht models for cluster dissolution

Abstract: The analysis of the age distributions of star cluster samples of different galaxies has resulted in two very different empirical models for the dissolution of star clusters: the Baltimore model and the Utrecht model. I describe these two models and their differences. The Baltimore model implies that the dissolution of star clusters is mass independent and that about 90% of the clusters are destroyed each age dex, up to an age of about a Gyr, after which point mass-dependent dissolution from two-body relaxation becomes the dominant mechanism. In the Utrecht model, cluster dissolution occurs in three stages: (i) mass-independent infant mortality due to the expulsion of gas up to about 107 yr; (ii) a phase of slow dynamical evolution with strong evolutionary fading of the clusters lasting up to about a Gyr; and (iii) a phase dominated by mass-dependent dissolution, as predicted by dynamical models. I describe the cluster age distributions for mass-limited and magnitude-limited cluster samples for both models. I refrain from judging the correctness of these models.

Bianchi type-I, III, V, VIo and Kantowski-Sachs universes in creation-field cosmology

Abstract: The solutions of Einstein’s equations in the presence of a creation field have been obtained for Bianchi type-I, III, V, VIo and Kantowski-Sachs (KS) universes in the quadrature form. Some physically interesting cases have been studied in detail.

Short-term effects of gamma ray bursts on Earth

Abstract: The aim of the present work is to study the potential short-term atmospheric and biospheric influence of Gamma Ray Bursts on the Earth. We focus in the ultraviolet flash at planet’s surface, which occurs as a result of the retransmission of the γ radiation through the atmosphere. This would be the only important short-term effect on life. We mostly consider Archean and Proterozoic eons, and for completeness we also comment on the Phanerozoic. Therefore, in our study we consider atmospheres with oxygen levels ranging from 10−5 to 1 of the present atmospheric level, representing different moments in the oxygen rise history. Ecological consequences and some strategies to estimate their importance are outlined.

Holographic dark energy scenario and variable modified Chaplygin gas

Abstract: In this letter, we have considered that the universe is filled with normal matter and variable modified Chaplygin gas. Also we have considered the interaction between normal matter and variable modified Chaplygin gas in FRW universe. Then we have considered a correspondence between the holographic dark energy density and interacting variable modified Chaplygin gas energy density. Then we have reconstructed the potential of the scalar field which describes the variable modified Chaplygin cosmology.

Dust acoustic solitary waves in dusty plasma with nonthermal ions

Abstract: In this paper, the characteristics of the dust acoustic solitary waves in dusty plasmas are studied. The distribution of ions is nonthermal, and the nonthermal parameter is treated as a variable. The pseudo-potential method has been used to investigate the possibility of soliton formation. We show that for some values of the nonthermal parameter there is no soliton.

Stellar dynamics in young clusters: the formation of massive runaways and very massive runaway mergers

Abstract: In the present paper we combine an N-body code that simulates the dynamics of young dense stellar systems with a massive star evolution handler that accounts in a realistic way for the effects of stellar wind mass loss. We discuss two topics. 1. The formation and the evolution of very massive stars (with masses >120 M⊙) is followed in detail. These very massive stars are formed in the cluster core as a consequence of the successive (physical) collisions of the 10–20 most massive stars in the cluster (this process is known as ‘runaway merging’). The further evolution is governed by stellar wind mass loss during core hydrogen and core helium burning (the WR phase of very massive stars). Our simulations reveal that, as a consequence of runaway merging in clusters with solar and supersolar values, massive black holes can be formed, but with a maximum mass ≈70 M⊙. In low-metallicity clusters, however, it cannot be excluded that the runaway-merging process is responsible for pair-instability supernovae or for the formation of intermediate-mass black holes with a mass of several 100 M⊙. 2. Massive runaways can be formed via the supernova explosion of one of the components in a binary system (the Blaauw scenario), or via dynamical interaction of a single star and a binary or between two binaries in a star cluster. We explore the possibility that the most massive runaways (e.g. ζ Pup, λ Cep, BD+43°3654) are the product of the collision and merger of two or three massive stars.

Ion acoustic solitary waves in plasma with nonthermal electron, positron and warm ion

Abstract: In this paper, the characteristics of ion acoustic solitary waves are studied in plasmas containing warm ion fluid, non-thermally distributed electron and positron. We study the effects of non-thermal electrons and ion temperature on solitons by Pseudo-potential method and show that the parametric region where ion acoustic solitons can exist is modified. We also obtain linear dispersion relation by using the standard normal-modes analysis.

Acceleration of particles in the vicinity of a massive black hole

Abstract: Recent results of the gamma-ray Cherenkov astronomy definitely prove the existence of fast variability in the very high energy (V.H.E.) gamma-ray flux of some active galactic nuclei. The BL Lac PKS 2155-304 for instance showed variations down to a few minutes time scale. From standard light travel time argument, these variations put extremely strong constraints on the size of the TeV emitting zone, which has to be of the order of a few Schwarzschild radius, even for high values of the relativistic Doppler factor of the emitting jets. Such discovery is a challenge for particle acceleration scenarios, which have to imagine efficient acceleration processes at work in a very compact zone. Eventually, the immediate vicinity of the central black hole appears as the most conservative choice for the location of the TeV emission region of active galactic nuclei. In this paper, we propose a two-step mechanism for charged particle acceleration in the magnetosphere of a massive black hole surrounded by an accretion disk. Particles first gain energy by a stochastic process during the accretion phase. It is shown that effective proton acceleration up to energies 1017–1019 eV is possible in a low-luminosity magnetized accretion disk with 2D turbulent motion. The distribution function of energetic protons over energies is a power law function with typical index ≃−1. Here electrons are not very efficiently accelerated because of their drastic losses by synchrotron radiation. In a second time, part of the fast particles escape from the disk and are then entrained by the magnetic structure above the disk, in the rotating black hole magnetosphere. They thus gain additional energy by direct centrifugal mechanism, up to about 1020 eV for the protons and to 10–100 TeV for the electrons when they cross the light cylinder surface. Such energetic particles can further radiate in the TeV spectral range observed by Cherenkov experiments as HESS, MAGIC and VERITAS. Energetic protons can produce γ-radiation in the energy band 1 GeV–100 TeV and above mainly by nuclei collisions with the disk matter, clouds, or ambient low energy photons. Energetic electrons can also reach the required spectral range by inverse Compton emission. However their acceleration is less efficient due to heavy radiation losses, and only gained by centrifugal process during the second phase of the whole mechanism we describe. Our present analysis would therefore favor hadronic scenarios for TeV emission of active galactic nuclei. It is tempting to relate long term variability over years of TeV active galactic nuclei to the first stochastic acceleration phase, which also provides the needed power law particle distributions, while short term variability over minutes is more likely due to perturbations of the second fast direct acceleration phase.

Bulk viscous barotropic magnetised string cosmological models

Abstract: Spatially homogeneous and anisotropic LRSBianchi type-I string cosmological models are studied in the frame work of general relativity when the source for the energy momentum tensor is a bulk viscous fluid containing one dimensional strings embedded in a magnetic field. A barotropic equation of state for the pressure and density is assumed to get determinate solutions of the field equations. The bulk viscous pressure is assumed to be proportional to the energy density. The effects of viscosity and electromagnetic field on the properties of the model are investigated. The role of bulk viscosity and electromagnetic field in getting an inflationary phase and in establishing a string phase in the universe is studied.

The Stellar Imager (SI) project: a deep space UV/Optical Interferometer (UVOI) to observe the Universe at 0.1 milli-arcsec angular resolution

Abstract: The Stellar Imager (SI) is a space-based, UV/Optical Interferometer (UVOI) designed to enable 01 milli-arcsecond (mas) spectral imaging of stellar surfaces and of the Universe in general It will also probe via asteroseismology flows and structures in stellar interiors SI’s science focuses on the role of magnetism in the Universe and will revolutionize our understanding of the formation of planetary systems, of the habitability and climatology of distant planets, and of many magneto-hydrodynamically controlled processes, such as accretion, in the Universe The ultra-sharp images of SI will revolutionize our view of many dynamic astrophysical processes by transforming point sources into extended sources, and snapshots into evolving views SI is a “Flagship and Landmark Discovery Mission” in the 2005 Heliophysics Roadmap and a potential implementation of the UVOI in the 2006 Science Program for NASA’s Astronomy and Physics Division We present here the science goals of the SI Mission, a mission architecture that could meet those goals, and the technology development needed to enable this mission Additional information on SI can be found at: http://hiresgsfcnasagov/si/

Probability distribution of terrestrial planets in habitable zones around host stars

Abstract: With more and more exoplanets being detected, it is paid closer attention to whether there are lives outside solar system. We try to obtain habitable zones and the probability distribution of terrestrial planets in habitable zones around host stars. Using Eggleton's code, we calculate the evolution of stars with masses less than 4.00 M (aS (TM)). We also use the fitting formulae of stellar luminosity and radius, the boundary flux of habitable zones, the distribution of semimajor axis and mass of planets and the initial mass function of stars. We obtain the luminosity and radius of stars with masses from 0.08 to 4.00 M (aS (TM)), and calculate the habitable zones of host stars, affected by stellar effective temperature. We achieve the probability distribution of terrestrial planets in habitable zones around host stars. We also calculate that the number of terrestrial planets in habitable zones of host stars is 45.5 billion, and the number of terrestrial planets in habitable zones around K type stars is the most, in the Milky Way.

Quasinormal modes of a black hole with quintessence-like matter and a deficit solid angle: scalar and gravitational perturbations

Abstract: In the previous paper (Li et al. in Phys. Lett. B 666:125–130, 2008), we show the solutions of Einstein equations with static spherically-symmetric quintessence-like matter surrounding a global monopole. Furthermore, this monopole become a black hole with quintessence-like matter and a deficit solid angle when it is swallowed by an ordinary black hole. We study its quasinormal modes by WKB method in this paper. The numerical results show that both the real part of the quasinormal frequencies and the imaginary part decrease as the state parameter w, for scalar and gravitational perturbations. And we also show variations of quasinormal frequencies of scalar and gravitational fields via different e (deficit solid angel parameter) and different ρ0 (density of static spherically-symmetric quintessence-like matter at r=1), respectively.