17717493
Slim disks with transition regions and applications to microquasars and narrow-line Seyfert 1 galaxies
Slim disks have been received much attention because of the increasing evidence of supercritical accreting objects. In this paper, we make an attempt to construct a unified model in which the viscosity and the dimensionless accretion rate can span rather wide ranges. We replace blackbody radiation under the diffusion approximation with a bridged formula that accounts for both blackbody radiation and thermal bremsstrahlung in optically thick and thin cases, respectively. Thus this allows us to investigate the structures of and the emergent spectra from slim disks in a wider parameter space covering transition regions from optically thick to optically thin. We show that there is a maximum transition radius, roughly R-tr,R-max/R-g similar to 50 when (M)(C) similar to 15. The emergent spectra from the unified model of the accretion disk have been calculated. A simple model of the hot corona above the slim disk is taken into account for the hard X-ray spectrum in this paper based on the work of Wang and Netzer. We have applied the present model to the microquasar GRS 1915+105 and the narrow-line Seyfert 1 galaxies RE J1034+396 and Ark 564. Our model can explain well the broadband X-ray spectra of narrow-line Seyfert 1 galaxies, microquasars, and possible ultraluminous compact X-ray sources. The present model can be widely applied to candidates for supercritical accreting objects.
119102309
Possible hard X-ray shortages in bursts from KS 1731-260 and 4U 1705-44
Aims. A hard X-ray shortage, implying the cooling of the corona, was observed during bursts of IGR J17473-272, 4U 1636-536, Aql X-1, and GS 1826-238. Apart from these four sources, we investigate here an atoll sample, in which the number of bursts for each source is larger than 5, to explore the possible additional hard X-ray shortage during Rossi X-ray timing explorer (RXTE) era. Methods. According to the source catalog that shows type-I bursts, we analyzed all the available pointing observations of these sources carried out by the RXTE proportional counter array. We grouped and combined the bursts according to their outburst states and searched for the possible hard X-ray shortage while bursting. Results. We found that the island states of KS 1731-260 and 4U 1705-44 show a hard X-ray shortage at significant levels of 4.5 and 4.7σ and a systematic time lag of 0.9 ± 2.1 s and 2.5 ± 2.0 s with respect to the soft X-rays, respectively. While in their banana branches and other sources, we did not find any consistent shortage.
17406200
EVOLUTION OF GASEOUS DISK VISCOSITY DRIVEN BY SUPERNOVA EXPLOSIONS IN STAR-FORMING GALAXIES AT HIGH REDSHIFT
Motivated by Genzel et al.'s observations of high-redshift star-forming galaxies, containing clumpy and turbulent rings or disks, we build a set of equations describing the dynamical evolution of gaseous disks with inclusion of star formation and its feedback. Transport of angular momentum is due to "turbulent" viscosity induced by supernova explosions in the star formation region. Analytical solutions of the equations are found for the initial cases of a gaseous ring and the integrated form for a gaseous disk, respectively. For a ring with enough low viscosity, it evolves in a slow process of gaseous diffusion and star formation near the initial radius. For a high viscosity, the ring rapidly diffuses in the early phase. The diffusion drives the ring into a region with a low viscosity and starts the second phase undergoing pile-up of gas at a radius following the decreased viscosity torque. The third is a sharply decreasing phase because of star formation consumption of gas and efficient transportation of gas inward forming a stellar disk. We apply the model to two z similar to 2 galaxies BX 482 and BzK 6004, and find that they are undergoing a decline in their star formation activity.
17396076
INTEGRAL and RXTE/ASM observations on IGR J17098−3628
To probe further the possible nature of the unidentified source IGR J17098-3628, we have carried out a detailed analysis of its long-term time variability as monitored by RXTE/ASM, and of its hard X-ray properties as observed by INTEGRAL. INTEGRAL has monitored this sky region over years and significantly detected IGR J17098-3628 only when the source was in this dubbed active state. In particular, at $\ge$ 20 keV, IBIS/ISGRI caught an outburst in March 2005, lasting for $\sim$5 days with detection significance of 73$\sigma$ (20-40 keV) and with the emission at $ $20 keV) outburst by $\sim$2 days. This resembles the behavior of X-ray novae like XN 1124-683, hence it further suggests a LMXB nature for IGR J17098-3628. While the quality of the ASM data prevents us from drawing any definite conclusions, these discoveries are important clues that, coupled with future observations, will help to resolve the as yet unknown nature of IGR J17098-3628.
16433217
The afterglows of ultraluminous quasars
Quasars represent a brief phase in the life cycle of most massive galaxies, but the evolutionary connection between central black holes and their host galaxies remains unclear. While quasars are active and shining brighter than the Compton-limit luminosity, their radiation heats the surrounding medium to the Compton temperature, forming Compton spheres extending to the Stromgren radius of Fe26+/He2+. After the quasars shut off, their "afterglow" can be detected through three signatures: (1) an extended X-ray envelope, with a characteristic temperature of ~3 × 107 K, (2) Lyα and Lyβ lines and the K edge of Fe26+, and (3) nebulosity from hydrogen and helium recombination emission lines. We discuss the possibility of detecting these signatures using Chandra, the planned X-Ray Evolving Universe Spectroscopy mission, and ground-based optical telescopes. The luminosity and size of quasar afterglows can be used to constrain the lifetime of quasars.
15715110
Suppressed star formation in circumnuclear regions in seyfert galaxies
Feedback from black hole activity is widely believed to play a key role in regulating star formation and black hole growth. A long-standing issue is the relation between star formation and the fueling of the supermassive black holes in active galactic nuclei (AGNs). We compile a sample of 57 Seyfert galaxies to tackle this issue. We estimate the surface densities of gas and star formation rates in circumnuclear regions (CNRs). Comparing them with the well-known Kennicutt-Schmidt (K-S) law, we find that the star formation rates (SFRs) in the CNRs of most Seyfert galaxies are suppressed in this sample. Feedback is suggested to explain the suppressed SFRs.
122789554
Observation of B ---> D(*) K- K0(*) decays
Abstract The B→D (∗) K − K (∗)0 decays have been observed for the first time. The branching fractions of the B→D (∗) K − K (∗)0 decay modes are measured. Significant signals are found for the B→D (∗) K − K ∗0 and B−→D0K−K0S decay modes. The invariant mass and polarization distributions for the K − K ∗0 and K−K0S subsystems have been studied. For the K − K ∗0 sybsystem these distributions agree well with those expected for two-body B→D (∗) a 1 − (1260) decays, with a 1 − (1260)→K − K ∗0 . The analysis was done using 29.4 fb−1 of data collected with the Belle detector at the e+e− asymmetric collider KEKB.
55319507
CONTROL AND ANALYSIS SYSTEM FOR DIGITAL FEEDBACK IN HLS
In HLS we employ the TED FPGA based processor for digital feedback system. To make feedback system work better and more easily, we developed the control and analysis system based on Matlab chiefly. The system do jobs as following: sampling data online and finishing its analysis; calculating FIR filter parameters and generating .CSV (format for FPGA) file to get the best gain and phase flexibly according to different beam working point; simulating the beam changes in different feedback gain and other stations to check whether the system work properly. INTRODUCION HLS uses the octopole magnet to help injection at the present time, but octopole magnet will cause nonlinearity and change the dynamic aperture, after the update plan of HLS finished, octopole magnet cannot be used anymore, then the feedback system should be used to suppress beam instabilities and improve injection efficiency. Compared to analog feedback system, digital feedback system is more simple and flexible, also it’s more reliable because of less affected by transport noise. We can use the fir filter in processor to get more feedback effect. So developing a control system fitting digital feedback for doing some analyzing is very useful for taking full advantage of digital feedback. CONTROL SYSTEM DESCRIPTION The structural diagram of digital feedback system is shown in Fig. 1 Figure 1: Structure block of digital feedback. After the beam signal is processed by RF front-end, it is sampled by 6 ADC in the feedback processor .The FPGA inside handles data and outputs it to kicker through DAC. During the process, command and data is transported in/out by USB2.0 interface when we need to change the system. In the processor made by TED the USB chip used is CY7C68 series, it’s the first micro processor controller interface chip with USB2.0 protocol inside in the world. The max transform speed can be 480 Mbps. The interface is Hot Swap so that it can protect the instrument and the control can be very flexible too. In the past the control soft we use is presented with machine. It is a command line programme and only contains some basic functions so that using of it is also very inconvenient while we need to debug the feedback machine; On the other hand the updated data which sampled by ADC is too much to analyze online, while sometimes we need to know some parameters of beam online, so we can develop an new control system to change the situation. To decrease the amounts of work as far as possible we take use of DLL part of the programme used before after reprogramming it. DLL (Dynamic Link Library) packages some executable codes and data in it while supplying us with calling in/out interface. The existed DLL is already compiled with C language based on driver of CY7C68 chip, so using it we don’t have to write driver again, that is not so easy. In our work we rewrite sublayer communication functions; they call basic I/O functions to control the system by CY7C68. The control system is carried out with Matlab. Matlab has a big advantage on data analyzing. In new edition Matlab such as 2008, support of calling function in DLL is more perfect. The contrast of data type used in C and MATLAB is in Fig. 2 Figure 2: Data type compared in c and Matlab. To make the structure of control system simple, we put most of the operation in DLL, so when using Matlab soft we just have to know the name of functions in DLL and what parameter we should pass to it. The soft uses MATLAB GUI (Graphical user interface) to make users easily operate it. Fig. 3 shows the panel of control GUI _________________________________________ *Work supported by National Natural Science Project (10175063) # mengming@mail.ustc.edu.cn . MOPE031 Proceedings of IPAC’10, Kyoto, Japan 1038 06 Beam Instrumentation and Feedback T03 Beam Diagnostics and Instrumentation Figure 3: Control system with Matlab. Its working chain is as follows: calling loadlibrary function to load DLL, calling calllib function to use functions in DLL, among which registerwrite, registerread function is for register reading and writing, adcmemoryupload function is for ADC data operating. First we should call deviceopen function to open device and establish connect; for DAC, address 0x8022 determines its on/off state. 0x8008,0x802A,0x800A,0x802C,0x800C are the output delay of DAC0-4 the last three bits of 0x8020 determine inverting state of 3 DAC 0x8012,0x8014 are the gain of DAC, 0x8004 0x801A determine the fir filter parameters; For ADC, 0x805C assigns the uploadsize of updating data, of which minimum value is 128K, 0x8058 are in charge of updating by writing 2,1,4 to it in queue, 0x805a shows the change of ADC station while translating data. Following the steps, we finish the control system. DATA ANALYSING With the data sampled by control system, we can do some analyse to get some important parameters of beam. Fir Coefficient In the processor, we use FIR filter in FPGA, the filter can separate unwanted DC constituent and other noise at cyclotron frequency, avoiding the saturation of ADC. It also has to exert right phase and gain on signal. FIR can be carried out easily when hundreds of Mb data should be processed in some ns time. In the FPGA, we employ least square method to design FIR filter . FIR can be expressed as
118518662
CHEERS RESULTS ON Mrk 573: A STUDY OF DEEP CHANDRA OBSERVATIONS
We present results on Mrk 573 obtained as part of the CHandra survey of Extended Emission-line Regions in nearby Seyfert galaxies (CHEERS). Previous studies showed that this source features a biconical emission in the soft X-ray band closely related to the narrow-line region as mapped by the [O III] emission line and the radio emission, though on a smaller scale; we investigate the properties of soft X-ray emission from this source with new deep Chandra observations. Making use of the subpixel resolution of the Chandra/ACIS image and point-spread function deconvolution, we resolve and study substructures in each ionizing cone. The two cone spectra are fitted with a photoionization model, showing a mildly photoionized phase diffused over the bicone. Thermal collisional gas at about ~1.1 keV and ~0.8 keV appears to be located between the nucleus and the "knots" resolved in radio observations, and between the "arcs" resolved in the optical images, respectively; this can be interpreted in terms of shock interaction with the host galactic plane. The nucleus shows a significant flux decrease across the observations indicating variability of the active galactic nucleus (AGN), with the nuclear region featuring a higher ionization parameter with respect to the bicone region. The long exposure allows us to find extended emission up to ~7 kpc from the nucleus along the bicone axis. Significant emission is also detected in the direction perpendicular to the ionizing cones, disagreeing with the fully obscuring torus prescribed in the AGN unified model and suggesting instead the presence of a clumpy structure.
125323507
Observation of B+ ---> proton anti-Lambda gamma
16824048
How Saturated Are Absorption Lines in the Broad Absorption Line Quasar PG 1411+442?
Recently, convincing evidence was found for extremely large X-ray absorption by column densities greater than 1023 cm-2 in broad absorption line quasars. One consequence of this is that any soft X-ray emission from these QSOs would be the scattered light or leaked light from partially covering absorbing material. A detection of the unabsorbed soft X-ray and absorbed hard X-ray component will allow us to determine the total column density as well as the effective covering factor of the absorbing material, which are difficult to obtain from the UV absorption lines. Brinkmann et al. recently showed that both the unabsorbed and absorbed components are detected in the nearby very bright broad absorption line quasar PG 1411+442. In this Letter, we make a further analysis of the broadband X-ray spectrum and the UV spectrum from the Hubble Space Telescope and demonstrate that broad absorption lines are completely saturated at the bottom of absorption troughs.