Results for "E. M. Xilouris"

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Calculating the submillimeter emissivity of dust grains in spiral galaxiesJan 04 2005We use the radiation transfer simulation of Xilouris et al. (1999) to constrain the quantity of dust in three nearby spiral galaxies (NGC 4013, NGC 5907 and NGC 891). The predicted visual optical depth from the model is compared with the thermal continuum ... More
A morphological comparison between the central region in AGN and normal galaxies using HST dataMar 21 2002We study the morphology of the central region of a sample of Active Galactic Nuclei (AGN) and a ``control'' sample of normal galaxies using archival observations of the WFPC2 instrument onboard the Hubble Space Telescope (HST). We use the ellipse fitting ... More
Radiation Transfer Models in GalaxiesJan 04 2005The dust in galaxies makes radiation transport calculations in them absolutely necessary. It is not only common practice in Astrophysics, but also wisdom, to try to make as simple models as possible to simulate physical systems. For spiral galaxies, however, ... More
Boxy/peanut "bulges": comparing the structure of galaxies with the underlying families of periodic orbitsDec 09 2005The vertical profiles of disc galaxies are built by the material trapped around stable periodic orbits, which form their "skeletons". According to this, the knowledge of the stability of the main families of periodic orbits in appropriate 3D models, can ... More
The X-ray variability and the near-IR to X-ray spectral energy distribution of four low luminosity Seyfert 1 galaxiesSep 10 2008We present the results from a study of the X-ray variability and the near-IR to X-ray spectral energy distribution of four low-luminosity, Seyfert 1 galaxies. We compared their variability amplitude and broad band spectrum with those of more luminous ... More
Cold and warm dust along a merging galaxy sequenceAug 16 2004We investigate the cold and warm dust properties during galaxy interactions using a merging galaxy sample ordered into a chronological sequence from pre- to post-mergers. Our sample comprises a total of 29 merging systems selected to have far-infrared ... More
Dust in a merging galaxy sequence: the SCUBA viewJan 04 2005We investigate the cold and warm dust properties during galaxy interactions using a merging galaxy sample ordered into a chronological sequence from pre- to post-mergers. Our sample comprises a total of 29 merging systems selected to have far-infrared ... More
Is the exponential distribution a good approximation of dusty galactic disks?Dec 01 1999We investigate how significant the spiral structure is on calculations concerning radiative transfer in dusty spiral galaxies seen edge-on. The widely adopted exponential disk model (i.e. both the stars and the dust are distributed exponentially in the ... More
Radio Emission Properties of Millisecond PulsarsFeb 04 2000We report the most recent progress in understanding the emission properties of millisecond pulsars.
Dust emission in early-type galaxies: The mid-infrared viewDec 01 2003We present mid-infrared (MIR) maps for a sample of 18 early-type galaxies observed at 4.5, 6.7 and 15 microns with the ISOCAM instrument on board the ISO satellite with a 6'' spatial resolution. We model the Spectral Energy Distribution (SED) of these ... More
The emissivity of dust grains in spiral galaxiesJun 17 2004We use the radiation transfer simulation of Xilouris et al. (1999) to constrain the quantity of dust in three nearby spiral galaxies (NGC 4013, NGC 5907 and NGC 4565). The predicted visual optical depth from the model is compared with the thermal continuum ... More
First optical detection from the supernova remnant G 15.1-1.6Jan 23 2008Deep optical CCD images of the supernova remnant G 15.1-1.6 were obtained and filamentary and diffuse emission has been discovered. The images, taken in the emission lines of Halpha+[N II], [S II] and [O III], reveal filamentary and diffuse structures ... More
New Planetary Nebulae in the Galactic Bulge region with l>0deg - IIJan 09 2006The presentation of new results from an [O III] 5007 A survey in a search for planetary nebulae (PNe) in the galactic bulge is continued. A total of 60 objects, including 19 new PNe, have been detected in the remaining 34 per cent of the survey area, ... More
Are spiral galaxies optically thin or thick?Jan 13 1999The opacity of spiral galaxies is examined by modelling the dust and stellar content of individual galaxies. The model is applied to five late-type spiral galaxies (NGC 4013, IC 2531, UGC 1082, NGC 5529 and NGC 5907). Having analyzed a total of seven ... More
X-ray selected Infrared Excess AGN in the Chandra Deep Fields: a moderate fraction of Compton-thick sourcesJul 02 2010We examine the properties of the X-ray detected, Infrared Excess AGN or Dust Obscured Galaxies (DOGs) in the Chandra Deep Fields (CDF). We find 26 X-ray selected sources which obey the 24 micron to R-band flux ratio criterion f_24/f_R>1000. These are ... More
Deep optical observations of the supernova remnants G 126.2+1.6, G 59.8+1.2 and G 54.4-0.3Aug 03 2005Optical CCD imaging and spectroscopic observations of three supernova remnants are presented. Optical emission from G 54.4-0.3 and G 59.8+1.2 is detected for the first time, while the first flux calibrated CCD images of the supernova remnant G 126.2+1.6 ... More
Is the Galactic submillimeter dust emissivity underestimated?Mar 31 2005We present detailed modeling of the spectral energy distribution (SED) of the spiral galaxies NGC 891, NGC 4013, and NGC 5907 in the far-infrared and submm wavelengths. The model takes into account the emission produced by the diffuse dust and the star ... More
Modelling the dust content of spiral galaxies: More dust mass vs. enhanced dust grain emissivityJan 04 2005We present detailed modelling of the spectral energy distribution (SED) of the spiral galaxies NGC 891, NGC 4013, and NGC 5907 in the far-infrared (FIR) and sub-millimeter (submm) wavelengths. The model takes into account the emission of the diffuse dust ... More
Dust properties of external galaxies; NGC 891 revisitedMar 20 2000We compare 850um SCUBA images of NGC 891 with the corresponding V-band optical depth predicted from radiation transfer simulations. These two tracers of dust show a very similar distribution along the minor axis and a reasonable agreement along the major ... More
The faint supernova remnant G 116.5+1.1 and the detection of a new candidate remnantFeb 03 2005The extended supernova remnant G 116.5+1.1 was observed in the optical emission lines of Halpha+[N II], [S II] and [O III]; deep long-slit spectra were also obtained. The morphology of the remnant's observed emission is mainly diffuse and patchy in contrast ... More
The distribution of the ISM in the Milky Way A three-dimensional large-scale modelJul 28 2006We use the COBE/DIRBE (1.2, 2.2, 60, 100, 140, and 240 $\mu$m) maps and the COBE/FIRAS spectra (for the wavelength range 100 - 1000 $\mu$m) to constrain a model for the spatial distribution of the dust, the stars, and the gas in the Milky Way. By assuming ... More
Millimeter and Submillimeter Excess Emission in M33 revealed by Planck and LABOCAMar 07 2016Previous studies have shown the existence of an excess of emission at submillimeter (submm) and millimeter (mm) wavelengths in the spectral energy distribution (SED) of many low-metallicity galaxies. The goal of the present study is to model separately ... More
B and I-band optical micro-variability observations of the BL Lac objects S5 2007+777 and 3C371Nov 04 2005We have observed S5 2007+777 and 3C371 in the B and I bands for 13 and 8 nights, respectively, during various observing runs in 2001, 2002 and 2004. The observations resulted in almost evenly sampled light curves, 6-9 hours long. We do not detect any ... More
A mid-IR study of Hickson Compact Groups I : Probing the Effects of Environment in Galaxy InteractionsMar 08 2010Aug 16 2010Hickson Compact Groups (HCGs) are among the densest galaxy environments of the local universe. To examine the effects of the environment on the infrared properties of these systems, we present an analysis of Spitzer and ISO mid-infrared imaging as well ... More
Discovery of optical emission from the supernova remnant G 32.8-0.1 (Kes 78)Mar 18 2009Deep optical CCD images of the supernova remnant G 32.8-0.1 were obtained where filamentary and diffuse emission was discovered. The images were acquired in the emission lines of Halpha+[N II] and [S II]. Filamentary and diffuse structures are detected ... More
Molecular gas heating in Arp 299Jul 08 2014Understanding the heating and cooling mechanisms in nearby (Ultra) luminous infrared galaxies can give us insight into the driving mechanisms in their more distant counterparts. Molecular emission lines play a crucial role in cooling excited gas, and ... More
PSR J1907+0918 - a young radio pulsar near SGR 1900+14 and G42.8+0.6May 19 2000Jul 12 2000We have extensively searched for periodic signals from the soft-gamma repeater SGR 1900+14, at 430 and 1410 MHz with the Arecibo telescope. Our observations did not reveal the 5.16-s periodicity discovered at X-ray wavelengths by Hurley et al. (1998). ... More
Tracing the molecular gas in distant submillimetre galaxies via CO(1-0) imaging with the EVLASep 03 2010Nov 15 2010We report the results of a pilot study with the EVLA of 12CO J=1-0 emission from four SMGs at z=2.2-2.5, each with an existing detection of CO J=3-2. Using the EVLA's most compact configuration we detect strong, broad J=1-0 line emission from all of our ... More
The molecular gas in Luminous Infrared Galaxies I: CO lines, extreme physical conditions, and their driversSep 19 2011Apr 05 2012We report results from a large molecular line survey of Luminous Infrared Galaxies (L_{IR} >= 10^{11} L_sol) in the local Universe (z<=0.1), conducted during the last decade with the James Clerk Maxwell Telescope (JCMT) and the IRAM 30-m telescope. This ... More
Abundant dust found in intergalactic spaceOct 02 2006Galactic dust constitutes approximately half of the elements more massive than helium produced in stellar nucleosynthesis. Notwithstanding the formation of dust grains in the dense, cool atmospheres of late-type stars, there still remain huge uncertainties ... More
Spectral Energy Distributions of a set of HII regions in M33 (HerM33es)Nov 23 2011Within the framework of the HerM33es Key Project for Herschel and in combination with multi-wavelength data, we study the Spectral Energy Distribution (SED) of a set of HII regions in the Local Group Galaxy M33. Using the Halpha emission, we perform a ... More
Molecular lines as tracers of Compton-thick AGN ?Sep 03 2010Recently, Papadopoulos et al., 2010 using sub-mm CO molecular line observations of nearby ultra-luminous IRAS galaxies, (U)LIRGs, have found that exceptionally large gas column densities (N_H > 10^25 cm-2) can be present across some of the very dense ... More
Constraining the properties of AGN host galaxies with Spectral Energy Distribution modelingJan 15 2015Jan 16 2015[abridged] We use the latest release of CIGALE, a galaxy SED fitting model relying on energy balance, to study the influence of an AGN in estimating both the SFR and stellar mass in galaxies, as well as the contribution of the AGN to the power output ... More
Variation in the dust spectral index across M33Nov 29 2011Using the Herschel PACS and SPIRE FIR/submm data, we investigate variations in the dust spectral index $\beta$ in the nearby spiral galaxy M33 at a linear resolution of 160 pc. We use an iteration method in two different approaches, single and two-component ... More
Dust heating sources in galaxies: the case of M33 (HERM33ES)Jul 12 2011Dust emission is one of the main windows to the physics of galaxies and to star formation as the radiation from young, hot stars is absorbed by the dust and reemitted at longer wavelengths. The recently launched Herschel satellite now provides a view ... More
Molecular gas heating mechanisms, and star formation feedback in merger/s tarbursts: NGC 6240 and Arp 193 as case studiesApr 24 2014We used the SPIRE/FTS instrument aboard the Herschel Space Observatory (HSO) to obtain the Spectral Line Energy Distributions (SLEDs) of CO from J=4-3 to J=13-12 of Arp 193 and NGC 6240, two classical merger/starbursts selected from our molecular line ... More
NELIOTA: First temperature measurement of lunar impact flashesOct 24 2017Jan 22 2018We report the first scientific results from the NELIOTA (NEO Lunar Impacts and Optical TrAnsients) project, which has recently begun lunar monitoring observations with the 1.2-m Kryoneri telescope. NELIOTA aims to detect faint impact flashes produced ... More
Variation in the dust emissivity index across M33 with Herschel and Spitzer (HerM33es)Oct 15 2013We study the wavelength dependence of the dust emission as a function of position and environment across the disk of M33 at a linear resolution of 160 pc using Spitzer and Herschel photometric data. Expressing the emissivity of the dust as a power law, ... More
Dust Properties in HII Regions in M33Jun 11 2016The conversion of the IR emission into star formation rate can be strongly dependent on the physical properties of the dust, which are affected by the environmental conditions where the dust is embedded. We study here the dust properties of a set of HII ... More
Gas and dust cooling along the major axis of M33 (HerM33es): ISO/LWS CII observationsMar 31 2013We aim to better understand the heating of the gas by observing the prominent gas cooling line [CII] at 158um in the low-metallicity environment of the Local Group spiral galaxy M33 at scales of 280pc. In particular, we aim at describing the variation ... More
Discovery of 10 pulsars in an Arecibo drift-scan surveyApr 01 2005We present the results of a 430-MHz survey for pulsars conducted during the upgrade to the 305-m Arecibo radio telescope. Our survey covered a total of 1147 square degrees of sky using a drift-scan technique. We detected 33 pulsars, 10 of which were not ... More
HERschel Observations of Edge-on Spirals (HEROES). I: Far-infrared morphology and dust mass determinationMay 14 2013Context. Edge-on spiral galaxies with prominent dust lanes provide us with an excellent opportunity to study the distribution and properties of the dust within them. The HEROES project was set up to observe a sample of seven large edge-on galaxies across ... More
Properties of compact 250 μm emission and HII regions in M33 (HERM33ES)May 13 2010Within the framework of the HERM33ES Key Project, using the high resolution and sensitivity of the Herschel photometric data, we study the compact emission in the Local Group spiral galaxy M33 to investigate the nature of the compact SPIRE emission sources. ... More
Measuring star formation with resolved observations: the test case of M33Feb 04 2015Context. Measuring star formation at a local scale is important to constrain star formation laws. Yet, it is not clear whether and how the measure of star formation is affected by the spatial scale at which a galaxy is observed. Aims. We want to understand ... More
NELIOTA: The wide-field, high-cadence lunar monitoring system at the prime focus of the Kryoneri telescopeSep 03 2018We present the technical specifications and first results of the ESA-funded, lunar monitoring project "NELIOTA" (NEO Lunar Impacts and Optical TrAnsients) at the National Observatory of Athens, which aims to determine the size-frequency distribution of ... More
The molecular gas in Luminous Infrared Galaxies II: extreme physical conditions, and their effects on the X_{co} factorFeb 08 2012Mar 13 2012In this work we conclude the analysis of our CO line survey of Luminous Infrared Galaxies (LIRGs: L_{IR}>=10^{11}L_{sol}) in the local Universe (Paper\,I), by focusing on the influence of their average ISM properties on the total molecular gas mass estimates ... More
CO Spectral Line Energy Distributions of IR-luminous galaxies and AGNMar 30 2010We report on new sensitive CO J=6-5 line observations of several luminous infrared Galaxies (LIRGs: L$_{\rm IR}$(8-1000$\mu $m$)\ga 10^{11}$ L$_{\odot}$), 36% (8/22) of them ULIRGs (L$_{\rm IR}$$>10^{12}$ L$_{\odot}$), and two powerful local AGN: the ... More
Tracing molecular gas mass in extreme extragalactic environments: an observational studyAug 12 2009Sep 21 2009We present a new observational study of the CO(1-0) line emission as an H2 gas mass tracer under extreme conditions in extragalactic environments. Our approach is to study the full neutral interstellar medium (H2, HI and dust) of two galaxies whose bulk ... More
The physical properties of Spitzer/IRS galaxies derived from their UV to 22 $μ$m spectral energy distributionSep 10 2016We provide the basic integrated physical properties of all the galaxies contained in the full CASSIS with available broad-band photometry from UV to 22 $\mu$m. We have collected photometric measurements in 14 wavelengths from available public surveys ... More
The Herschel Virgo Cluster Survey XII: FIR properties of optically-selected Virgo Cluster galaxiesSep 20 2012The Herschel Virgo Cluster Survey (HeViCS) is the deepest, confusion-limited survey of the Virgo Cluster at far-infrared (FIR) wavelengths. The entire survey at full depth covers $\sim$55 sq. deg. in 5 bands (100-500 \micron), encompassing the areas around ... More
Cool gas and dust in M33: Results from the Herschel M33 extended survey (HERM33ES)May 19 2010We present an analysis of the first space-based far-IR-submm observations of M 33, which measure the emission from the cool dust and resolve the giant molecular cloud complexes. With roughly half-solar abundances, M33 is a first step towards young low-metallicity ... More
Gone with the heat: A fundamental constraint on the imaging of dust and molecular gas in the early UniverseMay 12 2016Jun 06 2016Images of dust continuum and carbon monoxide (CO) line emission are powerful tools for deducing structural characteristics of galaxies, such as disk sizes, H$_2$ gas velocity fields and enclosed H$_2$ and dynamical masses. We report on a fundamental constraint ... More
Cool and warm dust emission from M33 (HerM33es)May 07 2012We study the far-infrared emission from the nearby spiral galaxy M33 in order to investigate the dust physical properties such as the temperature and the luminosity density across the galaxy. Taking advantage of the unique wavelength coverage (100, 160, ... More
Molecular and Atomic Gas in the Local Group Galaxy M33Mar 16 2010Jun 14 2010We present high resolution large scale observations of the molecular and atomic gas in the Local Group Galaxy M33. The observations were carried out using the HERA at the 30m IRAM telescope in the CO(2-1) line achieving a resolution of 12"x2.6 km/s, enabling ... More
Old and young stellar populations in DustPedia galaxies and their role in dust heatingMar 14 2019Within the framework of the DustPedia project we investigate the properties of cosmic dust and its interaction with the stellar radiation (originating from different stellar populations) for 814 galaxies in the nearby Universe, all observed by the Herschel ... More
100 mum and 160 mum emission as resolved star-formation rate estimators in M33 (HERM33ES)May 12 2010Over the past few years several studies have provided estimates of the SFR (star-formation rate) or the total infrared luminosity from just one infrared band. However these relations are generally derived for entire galaxies, which are known to contain ... More
Dust emission profiles of DustPedia galaxiesNov 21 2018Most radiative transfer models assume that dust in spiral galaxies is distributed exponentially. In this paper our goal is to verify this assumption by analysing the two-dimensional large-scale distribution of dust in galaxies from the DustPedia sample. ... More
The extent of dust in NGC 891 from Herschel/SPIRE imagesJun 08 2011Jun 14 2011We analyse Herschel/SPIRE images of the edge-on spiral galaxy NGC 891 at 250, 350 and 500 micron. Using a 3D radiative transfer model we confirm that the dust has a radial fall-off similar to the stellar disk. The dust disk shows a break at about 12 kpc ... More
The characteristics of millisecond pulsar emission: III.From low to high frequenciesJun 28 1999In this paper we present the first observations of a large sample of millisecond pulsars at frequencies of 2.7 GHz and 4.9 GHz. Our new flux measurements extend the known spectra for millisecond pulsars to the highest frequencies to date. The coverage ... More
The characteristics of millisecond pulsar emission: II. PolarimetryJan 19 1998We have made polarimetric monitoring observations of millisecond pulsars visible from the northern hemisphere at 1410 MHz. Their emission properties are compared with those of normal pulsars. Although we demonstrated in paper I that millisecond pulsars ... More
The Herschel Fornax Cluster Survey I: The Bright Galaxy SampleOct 16 2012We present Herschel observations of the Fornax cluster at 100, 160, 250, 350 and 500u with a spatial resolution of 7 - 36 arc sec (10" = 1 kpc at d_Fornax=17.9 Mpc). We define a sample of 11 bright galaxies, selected at 500u, directly comparable with ... More
Dust and gas power-spectrum in M33 (HERM33ES)Jan 12 2012Power spectra of de-projected images of late-type galaxies in gas and/or dust emission are very useful diagnostics of the dynamics and stability of their interstellar medium. Previous studies have shown that the power spectra can be approximated as two ... More
Old and young stellar populations in DustPedia galaxies and their role in dust heatingMar 14 2019Apr 16 2019Within the framework of the DustPedia project we investigate the properties of cosmic dust and its interaction with the stellar radiation (originating from different stellar populations) for 814 galaxies in the nearby Universe, all observed by the Herschel ... More
The characteristics of millisecond pulsar emission: I. Spectra, pulse shapes and the beaming fractionJan 19 1998We have monitored a large sample of millisecond pulsars using the 100-m Effelsberg radio telescope in order to compare their radio emission properties to the slowly rotating population. With some notable exceptions, our findings suggest that the two groups ... More
Star formation relations and CO SLEDs across the J-ladder and redshiftJul 16 2014We present FIR-CO luminosity relations ($\log L_{\rm FIR} = \alpha \log L'_{\rm CO} + \beta$) for the full CO rotational ladder from J=1-0 to J=13-12 for 62 local (z < 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs) using data from Herschel SPIRE-FTS ... More
Spectral Energy Distributions of HII regions in M33 (HerM33es)Jan 24 2013Within the framework of the Herschel M 33 extended survey HerM33es we study the Spectral Energy Distribution (SED) of a set of HII regions in M 33 as a function of the morphology. We present a catalogue of 119 HII regions morphologically classified: 9 ... More
DustPedia - the relationships between stars, gas and dust for galaxies residing in different environmentsApr 30 2019We use a sub-set of the DustPedia galaxy sample (461 galaxies) to investigate the effect the environment has had on galaxies. We consider Virgo cluster and field samples and also assign a density contrast parameter to each galaxy, as defined by the local ... More
Radial distribution of dust, stars, gas, and star-formation rate in DustPedia face-on galaxiesJun 16 2017The purpose of this work is the characterization of the radial distribution of dust, stars, gas, and star-formation rate (SFR) in a sub-sample of 18 face-on spiral galaxies extracted from the DustPedia sample. This study is performed by exploiting the ... More
The fraction of bolometric luminosity absorbed by dust in DustPedia galaxiesOct 02 2018We study the fraction of stellar radiation absorbed by dust, f_abs, in 814 galaxies of different morphological types. The targets constitute the vast majority (93%) of the DustPedia sample, including almost all large (optical diameter larger than 1'), ... More
A systematic metallicity study of DustPedia galaxies reveals evolution in the dust-to-metal ratiosJan 25 2019Observations of evolution in the dust-to-metal ratio allow us to constrain the dominant dust processing mechanisms. In this work, we present a study of the dust-to-metal and dust-to-gas ratios in a sub-sample of ~500 DustPedia galaxies. Using literature ... More
Arecibo HI Absorption Measurements of Pulsars and the Electron Density at Intermediate Longitudes in the First Galactic QuadrantSep 24 2007We have used the Arecibo telescope to measure the HI absorption spectra of eight pulsars. We show how kinematic distance measurements depend upon the values of the galactic constants R_o and Theta_o, and we select our preferred current values from the ... More
The Herschel Virgo Cluster Survey: VII. Dust in cluster dwarf elliptical galaxiesMay 17 2010We use the Science Demonstration Phase data of the Herschel Virgo Cluster Survey to search for dust emission of early-type dwarf galaxies in the central regions of the Virgo Cluster as an alternative way of identifying the interstellar medium.We present ... More
The Herschel Virgo Cluster Survey: IV. Resolved dust analysis of spiral galaxiesMay 17 2010We present a resolved dust analysis of three of the largest angular size spiral galaxies, NGC 4501 and NGC 4567/8, in the Herschel Virgo Cluster Survey (HeViCS) Science Demonstration field. Herschel has unprecedented spatial resolution at far-infrared ... More
The Herschel Virgo Cluster Survey: II. Truncated dust disks in HI-deficient spiralsMay 17 2010By combining Herschel-SPIRE observations obtained as part of the Herschel Virgo Cluster Survey with 21 cm HI data from the literature, we investigate the role of the cluster environment on the dust content of Virgo spiral galaxies.We show for the first ... More
The far-infrared view of M87 as seen by the Herschel Space ObservatoryOct 05 2010The origin of the far-infrared emission from the nearby radio galaxy M87 remains a matter of debate. Some studies find evidence of a far-infrared excess due to thermal dust emission, whereas others propose that the far-infrared emission can be explained ... More
The Herschel Virgo Cluster Survey: III. A constraint on dust grain lifetime in early-type galaxiesMay 17 2010Passive early-type galaxies (ETGs) provide an ideal laboratory for studying the interplay between dust formation around evolved stars and its subsequent destruction in a hot gas. Using Spitzer-IRS and Herschel data we compare the dust production rate ... More
The Herschel Virgo Cluster Survey: I. Luminosity functionsMay 17 2010We describe the Herschel Virgo Cluster Survey (HeViCS) and the first data obtained as part of the Science Demonstration Phase (SDP). The data cover a central 4x4 sq deg region of the cluster. We use SPIRE and PACS photometry data to produce 100, 160, ... More
The Herschel Virgo cluster survey: V. Star-forming dwarf galaxies - dust in metal-poor environmentsMay 17 2010We present the dust properties of a small sample of Virgo cluster dwarf galaxies drawn from the science demonstration phase data set of the Herschel Virgo Cluster Survey. These galaxies have low metallicities (7.8 < 12 + log(O/H) < 8.3) and star-formation ... More
The Herschel Virgo Cluster Survey: VI. The far-infrared view of M87May 17 2010The origin of the far-infrared emission from the nearby radio galaxy M87 remains a matter of debate. Some studies find evidence of a far-infrared excess due to thermal dust emission, whereas others propose that the far-infrared emission can be explained ... More
The Herschel Comprehensive (U)LIRG Emission Survey (HerCULES): CO Ladders, fine structure lines, and neutral gas coolingJan 13 2015(Ultra) Luminous Infrared Galaxies ((U)LIRGs) are objects characterized by their extreme infrared (8-1000 $\mu$m) luminosities ($L_{LIRG}>10^{11} $L$_\odot$ and $L_{ULIRG}>10^{12}$ L$_\odot$). The Herschel Comprehensive ULIRG Emission Survey (HerCULES; ... More
Timing of the young pulsar J1907+0918Nov 03 1999We have extensively searched for periodic signals in the area of the soft gamma-ray repeater SGR 1900+14, at 430 and 1410 MHz with the Arecibo telescope. Our observations did not reveal the 5.16-s periodicity reported for the magnetar down to a 430-MHz ... More
The Herschel Reference Survey: Dust in Early-Type Galaxies and Across the Hubble SequenceDec 06 2011Feb 06 2012We present Herschel observations of 62 Early-Type Galaxies (ETGs), including 39 galaxies morphologically classified as S0+S0a and 23 galaxies classified as ellipticals using SPIRE at 250, 350 and 500 microns (and PACS 100 and 160 microns for 19 sources) ... More
Spatially resolving the dust properties and submillimetre excess in M 33Jan 15 2018The relative abundance of the dust grain types in the interstellar medium (ISM) is directly linked to physical quantities that trace the evolution of galaxies. We study the dust properties of the whole disc of M33 at spatial scales of ~170 pc. This analysis ... More
New Binary and Millisecond Pulsars from Arecibo Drift-Scan SearchesApr 08 2004We discuss four recycled pulsars found in Arecibo drift-scan searches. PSR J1944+0907 has a spin period of 5.2 ms and is isolated. The 5.8-ms pulsar J1453+19 may have a low-mass companion. We discuss these pulsars in the context of isolated millisecond ... More
PSR J0609+2130: A disrupted binary pulsar?Aug 18 2003Nov 12 2003We report the discovery and initial timing observations of a 55.7-ms pulsar, J0609+2130, found during a 430-MHz drift-scan survey with the Arecibo radio telescope. With a spin-down rate of $3.1 \times 10^{-19}$ s s$^{-1}$ and an inferred surface dipole ... More
New HErschel Multi-wavelength Extragalactic Survey of Edge-on Spirals (NHEMESES)Sep 26 2011Sep 27 2011Edge-on spiral galaxies offer a unique perspective on the vertical structure of spiral disks, both stars and the iconic dark dustlanes. The thickness of these dustlanes can now be resolved for the first time with Herschel in far-infrared and sub-mm emission. ... More
A flexible format for exchanging pulsar dataJan 12 1998We describe a data format currently in use amongst European institutions for exchanging and archiving pulsar data. The format is designed to be as flexible as possible with regard to present and future compatibility with different operating systems. One ... More
New Pulsars Discovered in Arecibo Drift-Scan SearchesOct 16 2003We report on new pulsars discovered in Arecibo drift-scan data. Processing of 2200 square degrees of data has resulted in the detection of 41 known and 12 new pulsars. New pulsars include two millisecond pulsars, one solitary and one binary recycled pulsar, ... More
Arecibo timing and single-pulse observations of 17 pulsarsAug 15 2005Aug 16 2005We report on timing and single-pulse observations of 17 pulsars discovered at the Arecibo observatory. The highlights of our sample are the recycled pulsars J1829+2456, J1944+0907 and the drifting subpulses observed in PSR J0815+0939. For the double neutron ... More
New Pulsars from Arecibo Drift-Scan SearchesNov 12 2002We report new pulsars discovered in drift-scan data taken by two collaborations (Berkeley/Cornell and STScI/NAIC) during the latter stages of the Arecibo upgrade period. The data were taken with the Penn State Pulsar Machine and are being processed on ... More
Profile instabilities of the millisecond pulsar PSR J1022+1001Mar 02 1999We present evidence that the integrated profiles of some millisecond pulsars exhibit severe changes that are inconsistent with the moding phenomenon as known from slowly rotating pulsars. We study these profile instabilities in particular for PSR J1022+1001 ... More
NELIOTA: ESA's new NEO lunar impact monitoring project with the 1.2m telescope at the National Observatory of AthensOct 13 2015NELIOTA is a new ESA activity launched at the National Observatory of Athens in February 2015 aiming to determine the distribution and frequency of small near-earth objects (NEOs) via lunar monitoring. The project involves upgrading the 1.2m Kryoneri ... More
PACS and SPIRE photometer maps of M33: First results of the Herschel M33 extended survey (HERM33ES)May 14 2010Within the framework of the HERM33ES key project, we are studying the star forming interstellar medium in the nearby, metal-poor spiral galaxy M33, exploiting the high resolution and sensitivity of Herschel. We use PACS and SPIRE maps at 100, 160, 250, ... More
Herschel observations of water vapour in Markarian 231May 20 2010The Ultra Luminous InfraRed Galaxy Mrk 231 reveals up to seven rotational lines of water (H2O) in emission, including a very high-lying (E_{upper}=640 K) line detected at a 4sigma level, within the Herschel/SPIRE wavelength range, whereas PACS observations ... More
Black hole accretion and star formation as drivers of gas excitation and chemistry in Mrk231May 17 2010We present a full high resolution SPIRE FTS spectrum of the nearby ultraluminous infrared galaxy Mrk231. In total 25 lines are detected, including CO J=5-4 through J=13-12, 7 rotational lines of H2O, 3 of OH+ and one line each of H2O+, CH+, and HF. We ... More
Arecibo timing observations of 17 pulsars along the Galactic planeDec 05 2001We present phase-coherent timing solutions obtained for the first time for 17 pulsars discovered at Arecibo by Hulse & Taylor (1975ab) in a 430-MHz survey of the Galactic plane. This survey remains the most sensitive of the Galactic plane at 430 MHz and ... More
The Heating of Mid-Infrared Dust in the Nearby Galaxy M33: A Testbed for Tracing Galaxy EvolutionFeb 19 2014Because the 8 {\mu}m polycyclic aromatic hydrocarbon (PAH) emission has been found to correlate with other well-known star formation tracers, it has widely been used as a star formation rate (SFR) tracer. There are, however, studies that challenge the ... More
The Early Interaction of the Planetary Nebula NGC 40 with the Interstellar MediumJan 15 2002We report the detection of an Halpha emission-line structure in the upstream side of the planetary nebula NGC 40, which is predicted by numerical simulations, and which is attributed to Rayleigh-Taylor instability. Such a Rayleigh-Taylor instability is ... More
The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). I: The UV luminosity function of the central 12 sq.degFeb 07 2011The GALEX Ultraviolet Virgo Cluster Survey (GUViCS) is a complete blind survey of the Virgo cluster covering about 40 sq. deg. in the far UV (FUV, lambda_eff=1539A, Delta-lambda=442A) and about 120 sq. deg. in the near UV (NUV, lambda_eff=2316A, Delta-lambda=1060A). ... More
Herschel/SPIRE Observations of the Dusty Disk of NGC 4244Apr 13 2012We present Herschel/SPIRE images at 250, 350, and 500 {\mu}m of NGC 4244, a typical low-mass, disk-only and edge-on spiral galaxy. The dust disk is clumpy and shows signs of truncation at the break radius of the stellar disk. This disk coincides with ... More