54883621
The X-ray reflector in NGC 4945: a time- and space-resolved portrait
We present a time, spectral and imaging analysis of the X-ray reflector in NGC 4945, which reveals its geometrical and physical structure with unprecedented detail. NGC 4945 hosts one of the brightest AGN in the sky above 10 keV, but it is only visible through its reflected/scattered emission below 10 keV, due to absorption by a column density of ∼4 × 10 24 cm −2 .An ew Suzaku campaign of five observations spanning ∼6 months, together with past XMM–Newton and Chandra observations, shows a remarkable constancy (within <10 per cent) of the reflected component. Instead, Swift-BAT reveals strong intrinsic variability on time-scales longer than 1 yr. Modelling the circumnuclear gas as a thin cylinder with the axis on the plane of the sky, we show that the reflector is at a distance ≥30–50 pc, well within the imaging capabilities of Chandra at the distance of NGC 4945 (1 arcsec ∼18 pc). Accordingly, the Chandra imaging reveals a resolved, flattened, ∼150 pc long clumpy structure, whose spectrum is fully due to cold reflection of the primary AGN emission. The clumpiness may explain the small covering factor derived from the spectral and variability properties.
11144784
A Chandra Study of the Rosette Star-forming Complex. I. The Stellar Population and Structure of the Young Open Cluster NGC 2244
We present the first high spatial resolution X-ray study of NGC 2244, the 2 Myr old stellar cluster in the Rosette Nebula, using Chandra. Over 900 X-ray sources are detected; 77% have optical or FLAMINGOS NIR stellar counterparts and are mostly previously uncataloged young cluster members. The X-ray-selected population is estimated to be nearly complete between 0.5 and 3 M☉. A number of further results emerge from our analysis: (1) The X-ray LF and the associated K-band LF indicate a normal Salpeter IMF for NGC 2244. This is inconsistent with the top-heavy IMF reported from earlier optical studies that lacked a good census of log (LX/Lbol) ~ − 7 relation. The Rosette OB X-ray spectra are soft and consistent with the standard model of small-scale shocks in the inner wind of a single massive star.
119214676
THE PROGRESSION OF STAR FORMATION IN THE ROSETTE MOLECULAR CLOUD
Using Spitzer Space Telescope and Chandra X-Ray Observatory data, we identify young stellar objects (YSOs) in the Rosette Molecular Cloud (RMC). By being able to select cluster members and classify them into YSO types, we are able to track the progression of star formation locally within the cluster environments and globally within the cloud. We employ the nearest neighbor method analysis to explore the density structure of the clusters and YSO ratio mapping to study age progressions in the cloud. We find a relationship between the YSO ratios and extinction that suggests star formation occurs preferentially in the densest parts of the cloud and that the column density of gas rapidly decreases as the region evolves. This suggests rapid removal of gas may account for the low star formation efficiencies observed in molecular clouds. We find that the overall age spread across the RMC is small. Our analysis suggests that star formation started throughout the complex around the same time. Age gradients in the cloud appear to be localized and any effect the H II region has on the star formation history is secondary to that of the primordial collapse of the cloud.
18395747
IMAGING THE CIRCUMNUCLEAR REGION OF NGC 1365 WITH CHANDRA
We present the first Chandra/ACIS imaging study of the circumnuclear region of the nearby Seyfert galaxy NGC 1365. The X-ray emission is resolved into pointlike sources and complex, extended emission. The X-ray morphology of the extended emission shows a biconical soft X-ray-emission region extending ~5 kpc in projection from the nucleus, coincident with the high-excitation outflow cones seen in optical emission lines particularly to the northwest. Harder X-ray emission is detected from a kpc-diameter circumnuclear ring, coincident with the star-forming ring prominent in the Spitzer mid-infrared (IR) images; this X-ray emission is partially obscured by the central dust lane of NGC 1365. Spectral fitting of spatially separated components indicates a thermal plasma origin for the soft extended X-ray emission (kT = 0.57 keV). Only a small amount of this emission can be due to photoionization by the nuclear source. Detailed comparison with [O III]λ5007 observations shows that the hot interstellar medium (ISM) is spatially anticorrelated with the [O III]-emitting clouds and has thermal pressures comparable to those of the [O III] media, suggesting that the hot ISM acts as a confining medium for the cooler photoionized clouds. The abundance ratios of the hot ISM are fully consistent with the theoretical values for enrichment from Type II supernovae, suggesting that the hot ISM is a wind from the starburst circumnuclear ring. X-ray emission from a ~450 pc long nuclear radio jet is also detected to the southeast.
12509772
AN INTRODUCTION TO THE CHANDRA CARINA COMPLEX PROJECT
The Great Nebula in Carina provides an exceptional view into the violent massive star formation and feedback that typifies giant H II regions and starburst galaxies. We have mapped the Carina star-forming complex in X-rays, using archival Chandra data and a mosaic of 20 new 60 ks pointings using the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer, as a testbed for understanding recent and ongoing star formation and to probe Carina's regions of bright diffuse X-ray emission. This study has yielded a catalog of properties of > 14,000 X-ray point sources;> 9800 of them have multiwavelength counterparts. Using Chandra's unsurpassed X-ray spatial resolution, we have separated these point sources from the extensive, spatially-complex diffuse emission that pervades the region; X-ray properties of this diffuse emission suggest that it traces feedback from Carina's massive stars. In this introductory paper, we motivate the survey design, describe the Chandra observations, and present some simple results, providing a foundation for the 15 papers that follow in this special issue and that present detailed catalogs, methods, and science results.
119266124
A DEEP CHANDRA ACIS STUDY OF NGC 4151. I. THE X-RAY MORPHOLOGY OF THE 3 kpc DIAMETER CIRCUM-NUCLEAR REGION AND RELATION TO THE COLD INTERSTELLAR MEDIUM
We report on the imaging analysis of ~200 ks sub-arcsecond resolution Chandra Advanced CCD Imaging Spectrometer (ACIS-S) observations of the nearby Seyfert 1 galaxy NGC 4151. Bright, structured soft X-ray emission is observed to extend from 30 pc to 1.3 kpc in the southwest from the nucleus, much farther than seen in earlier X-ray studies. The terminus of the northeastern X-ray emission is spatially coincident with a CO gas lane, where the outflow likely encounters dense gas in the host galactic disk. X-ray emission is also detected outside the boundaries of the ionization cone, which indicates that the gas there is not completely shielded from the nuclear continuum, as would be the case for a molecular torus collimating the bicone. In the central r < 200 pc region, the subpixel processing of the ACIS data recovers the morphological details on scales of <30 pc (<05) first discovered in Chandra High Resolution Camera images. The X-ray emission is more absorbed toward the boundaries of the ionization cone, as well as perpendicular to the bicone along the direction of a putative torus in NGC 4151. The innermost region where X-ray emission shows the highest hardness ratio is spatially coincident with the near-infrared-resolved H2 emission and dusty spirals we find in an Hubble Space Telescope V – H color image. The agreement between the observed H2 line flux and the value predicted from X-ray-irradiated molecular cloud models supports photo-excitation by X-rays from the active nucleus as the origin of the H2 line, although contribution from UV fluorescence or collisional excitation cannot be ruled out with current data. The discrepancy between the mass of cold molecular gas inferred from recent CO and near-infrared H2 observations may be explained by the anomalous CO abundance in this X-ray-dominated region. The total H2 mass derived from the X-ray observation agrees with the recent measurement by Storchi-Bergmann et al.
209963341
Measurement of B(Upsilon(5S) ---> B(*)(s) anti-B(*)(s)) Using phi Mesons
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
119278481
The X-ray nature of the nucleus in Seyfert 2 galaxy NGC 7590
We present the results of the Chandra high-resolution observation of the Seyfert 2 galaxy NGC 7590. This object was reported to show no X-ray absorption in the low-spatial resolution ASCA data. The XMM-Newton observations show that the X-ray emission of NGC 7590 is dominated by an off-nuclear ultra-luminous X-ray source (ULX) and extended emissions from the host galaxy, and the nucleus is rather weak, likely hosting a Compton-thick AGN. Our recent Chandra observation of NGC 7590 enables us to effectively remove the X-ray contamination from the ULX and the extended component. The nuclear source remains undetected at the flux level of ~ 4 × 10 −15 erg cm −2 s −1 . Although not detected, the Chandra data give a 2–10 keV flux upper limit of ~ 6.1 × 10 −15 erg cm −2 s −1 (at a 3σ level), a factor of three less than the XMM-Newton value, strongly supporting the Compton-thick nature of the nucleus. In addition, we detected five off-nuclear X-ray point sources within the galaxy’s D 25 ellipse, all with 2 – 10 keV luminosity above 2 × 10 38 erg s −1 (assuming the distance of NGC 7590). In particular, the ULX previously identified by ROSAT data is resolved by Chandr a into two distinct X-ray sources. Our analysis highlights the importance of high spatial resolution images in discovering and studying ULXs.
119176140
A general relativistic external Compton-scattering model for TeV emission from M87
M87 is the first detected non-blazar extragalactic Tera-Ele ctron-Volt (TeV) source with rapid variation and very flat spectrum in the TeV band. To explain the two-peaks in the spectral energy distribution (SED) of the nucleus of M87 which is similar to those of blazars, the most commonly adopted models are the synchrotron self-Compton scattering (SSC) models and the external inverse Compton scattering (EIC) models. Considering that there is no correlated variation in the soft band (from r adio to X-ray) matching the TeV variation, and the TeV sources should not suffer from the γγ absorption due to the flat TeV spectrum, the EIC models are advantageous in modeling the TeV emission from M87. In this paper, we propose a self-consistent EIC model to explain the flat TeV spectrum of M87 within the framework of fully general relativity, where the background soft photons are from the advection-dominated accretion flo w (ADAF) around the central black hole, and the high energy electrons are from the mini-jets which are powered by the magnetic reconnection in the main jet (Giannios et al. 2010). In our model, both the TeV flares obser ved in the years of 2005 and 2008 could be well explained: the γγ absorption for TeV photons is very low, even inside the region very close to the black hole 20Rg ∼ 50Rg; at the same region, the average EIC cooling time (∼ 10 2 ∼ 10 3 s) is short, which is consistent with the observed time scale of TeV variation. Furthermore, we also discuss the possibility that the accompanying X-ray flare in 2008 is due to the direct synchrotron radiation of the mini-jets. Subject headings:black hole physics — galaxies: individual (M87)
18385480
Rapidly variable Fe K$\alpha$ line in NGC 4051
We present a detailed analysis on the variability of the Fe K emission line in NGC 4051 using ASCA data. Through simple Gaussian line fits, we find not only obvious Fe K line variability with no significant difference in the X-ray continuum flux between two ASCA observations which were separated by $\sim$ 440 days, but also rapid variability of Fe K line on time scales $\sim 10^4$ s within the second observation. During the second observation, the line is strong (EW = 733$^{+206}_{-219}$ eV) and broad ($\sigma = 0.96^{+0.49}_{-0.35}$ keV) when the source is brightest, and become weaker (EW = 165$^{+87}_{-86}$ eV) and narrower ($\sigma<0.09$ keV) whilst the source is weakest. The equivalent width of Fe K line correlates positively with the continuum flux, which shows an opposite trend with another Seyfert 1 galaxy MCG --6-30-15.