High IRAS Research Articles

Germ-line biomarkers disrupting microRNA regulatory pathways to predict toxicity and response to anti-PD-1 and anti-PD-L1 therapies.

3040 Background: Identifying responders to developing immune therapies is of high priority, yet identifying patients who will suffer from toxicity, which represents a unique spectrum of side effects, termed immune-related adverse events (irAEs), is critical. The complex host-specific response to immune therapies led us to hypothesize that germ-line mutations, present in both the tumor and in the host’s immune system, may be a source of biomarkers. As there is compelling evidence that recently discovered germ-line mutations disrupting microRNA (miRNA) networks act as biomarkers of treatment response and baseline immune status, we evaluated such mutations in patients treated with these therapies. Methods: Patients treated with anti-PD1 or anti-PDL1 therapy alone and clinically documented response and toxicity were tested with a panel of over 150 vetted germ-line miRNA based biomarkers. Of 85 patients evaluated for response, 75 had melanoma, and 10 had NSCLC. For analysis of toxicity, an additional 4 patients with other cancer types were included. Subjects were classified as responders (Complete, Partial) versus non-responders (Progressive, Stable), or as experiencing low irAEs (grade 0 and 1) versus high irAEs (grade 2 and above). We used Chi-squared analysis for base evaluation and then compared three classification techniques including classification trees, random forests and Bayesian probit regression with non-local priors. We estimated classification performance via leave-one-out cross validation. Results: By Chi-Squared analysis we found over a dozen biomarkers associated with response, and a dozen biomarkers associated with toxicity. These included germ-line mutations in 3’ untranslated regions as well as in miRNA promoter regions. We found that both classification trees and Bayesian probit compared reasonably well with random forests. We found a response signature with a specificity of 89% by Random Forests, and a toxicity signature with a specificity of 76% by Random Forests. Conclusions: We have shown that a new class of germ-line mutations disrupting miRNA regulatory networks can act as biomarkers of response and toxicity to anti-PD1 and anti-PDL1 therapy.

DETECTION OF MOLECULAR GAS IN VOID GALAXIES: IMPLICATIONS FOR STAR FORMATION IN ISOLATED ENVIRONMENTS

We present the detection of molecular gas from galaxies located in nearby voids using the CO line emission as a tracer. The observations were done using the 45m Nobeyama Radio Telescope. Void galaxies lie in the most under dense parts of our universe and a significant fraction of them are gas rich, late type spiral galaxies. Although isolated, they have ongoing star formation but appear to be slowly evolving compared to galaxies in denser environments. Not much is known about their star formation properties or cold gas content. In this study we searched for molecular gas in five void galaxies. The galaxies were selected based on their relatively high IRAS fluxes or Ha line luminosities, both of which signify ongoing star formation. All five galaxies appear to be isolated and two lie within the Bootes void. We detected CO line emission from four of the five galaxies in our sample and the molecular gas masses lie between 10^8 to 10^9 Msolar. We did follow-up Ha imaging observations of three detected galaxies using the Himalayan Chandra Telescope and determined their star formation rates (SFRs). The SFR varies from 0.2 to 1 Msolar/yr, which is similar to that observed in local galaxies. Our study indicates that although void galaxies reside in under dense regions, their disks contain molecular gas and have star formation rates similar to galaxies in denser environments.

Inhomogeneities on the surface of 21 Lutetia, the asteroid target of the Rosetta mission

<i>Context. <i/> In July 2010 the ESA spacecraft Rosetta will fly by the main belt asteroid 21 Lutetia. Several observations of this asteroid have been performed so far, but its surface composition and nature are still a matter of debate. For a long time Lutetia was supposed to have a metallic nature due to its high IRAS albedo. Later on it has been suggested that the asteroid has a surface composition similar to primitive carbonaceous chondrite meteorites, while further observations proposed a possible genetic link with more evolved enstatite chondrite meteorites.<i>Aims. <i/>We performed visible spectroscopic observations of 21 Lutetia in November 2008 at the Telescopio Nazionale Galileo (TNG, La Palma, Spain) to make a decisive contribution to solving the conundrum of its nature. <i>Methods. <i/>Thirteen visible spectra were acquired at different rotational phases and subsequently analyzed.<i>Results. <i/>We confirm a narrow spectral feature at about 0.47–0.48 <i>μ<i/>m which was already found by Lazzarin et al. (2004, A&A, 425, L25) in the spectra of Lutetia. We also confirm an earlier find of Lazzarin et al. (2004), who detected a spectral feature at about 0.6 <i>μ<i/>m in one of their Lutetia's spectra. More remarkable is the difference of our spectra though, which exhibit different spectral slopes between 0.6 and 0.75 <i>μ<i/>m and, in particular, we found that up to 20% of the Lutetia surface could have flatter spectra.<i>Conclusions. <i/>We detected a variation of the spectral slopes at different rotational phases that could be interpreted as possibly due to differences in the chemical/mineralogical composition as well as to inhomogeneities of the structure of the Lutetia's surface (e.g., to craters or albedo spots) in the southern hemisphere.

Extended Dust Shells around Carbon Stars in the Infrared and in Optical Light

We investigate the structure of extended dust shells around optical carbon stars in the far-infrared and in optical light. In the optical we have discovered that R Scl and U Ant are associated with circularly extended emission, the radii of which are about 20″ and 58″, respectively. The emission is probably scattered light of the central star by dust grains in their circumstellar shells. In the far-infrared we have discovered a double shell structure surrounding U Ant in high resolution IRAS images, which is direct evidence of a periodic change of mass-loss on a time-scale of the order of 104 years in the AGB evolution. Relating the two shells to two consecutive thermal pulses allows for a self-consistent determination of the interpulse period, core-mass, luminosity, and distance. Direct mapping of Y CVn at 90 and 160 μm with ISOPHOT on board ISO has revealed a very extended detached dust shell around this star. The mass-loss rate is found to have decreased drastically by two orders of magnitude 1.4×104 years ago, which should be an important clue to the understanding of J-type stars.

The Interstellar Environment of Filled-Center Supernova = +1.1

A multi-wavelength investigation of the candidate supernova remnant G63.7+1.1 and its surrounding interstellar medium is presented. On the basis of radio continuum data we conclude that the object is a filled-center supernova remnant, perhaps in the course of becoming a composite remnant. The morphology of the remnant, along with HI, 12CO and high resolution IRAS data, suggest that G63.7+1.1 is interacting directly with the ISM, and does not lie in a low density region of the ISM. This in turn strongly suggests that the detected nebula is not surrounded by an invisible halo of supernova ejecta. The association between the SNR and HI and CO features near the tangent point implies a kinematic distance for G63.7+1.1 of 3.8 +/- 1.5 kpc.

Spatial distribution of far-infrared emission in spiral galaxies. I. Relation with radio continuum emission.

We use high resolution IRAS and 20 cm radio continuum (RC) images of a sample of 22 spiral galaxies to study the correlation between the far infra-red (FIR) and RC emissions within the galactic disks. A combination of exponential and gaussian profiles rather than a single exponential profile is found to be a better representation of the observed intensity profiles in the two bands. The gaussian component, which we show is not due to the effects of limited beam-resolution, contains more than 60% of the total flux in majority of the galaxies. The dominance of the gaussian component suggests that the nuclear star forming regions and the bulge stars are more important contributors to the emission in the two bands, rather than the outer exponential stellar disks. The RC profile is flatter compared to the FIR profile, resulting in a decrease of their ratio, Q60, away from the center. However, the Q60 increases in the extreme outer parts, where the dispersion in the FIR and RC correlation is also higher than in the central regions. The global Q60 and its dispersion match those in the inner parts of the galaxies. These results imply that the observed tight correlation in the global quantities reflects processes in the inner regions only where OB stars and the associated Type II supernovae control the FIR and RC emission. In the outer parts heating of very small dust grains by the old disk stars provides a secondary component in the FIR emission, without associated RC emission. The edge-on galaxy NGC3079 shows extended FIR and RC emissions along its minor axis, probably associated with the nuclear starburst activity.

A Parsec-Size Bow Shock around Betelgeuse

view Abstract Citations (64) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Parsec-Size Bow Shock around Betelgeuse Noriega-Crespo, Alberto ; van Buren, Dave ; Cao, Yu ; Dgani, Ruth Abstract We present new High Resolution IRAS (HiRes) images at 60 and 100 \mum of a bow shock or shell with a mean radius of 6arcmin surrounding Betelgeuse (alpha Orionis). The outermost section of this structure is at ~ 7arcmin which corresponds to a physical scale of 0.8 pc at a distance of 400 pc. The images were made by applying a relative Burg entropy maximization algorithm to suppress the ringing around bright sources and allow the detection of nearby low surface brightness features. The shell is relatively narrow at 60 \mum (at the 1arcmin HiRes resolution), asymmetric and oriented along the star's direction of motion. We propose that the shell is confined by the ram pressure of the interstellar medium. Using a shell flux of 110 Jy (at 60 \mum) within a radius of 7.arcmin5 we estimate mass of 0.14 \msol for the shell. Publication: The Astronomical Journal Pub Date: August 1997 DOI: 10.1086/118517 Bibcode: 1997AJ....114..837N Keywords: TURBULENCE; ISM: STRUCTURE; STARS: INDIVIDUAL: BETELGEUSE full text sources ADS | data products SIMBAD (1)

PARALLELIZATION AND ALGORITHMIC ENHANCEMENTS OF HIGH RESOLUTION IRAS IMAGE CONSTRUCTION

ABSTRACT The Infrared Astronomical Satellite carried out a nearly complete survey of the infrared sky, and the survey data are important for the study of many astrophysical phenomena. However, many data sets at other wavelengths have higher resolutions than that of the co-added IRAS maps, and high resolution IRAS images are strongly desired both for their own information content and their usefulness in correlation studies. The HIRES program was developed by the Infrared Processing and Analysis Center (IPAC) to produce high resolution (~1') images from IRAS data using the Maximum Correlation Method (MCM). We describe the port of HIRES to the Intel Paragon, a massively parallel supercomputer, other software developments for mass production of HIRES images, and the IRAS Galaxy Atlas, a project to map the Galactic plane at 60 and 100 microns. Images produced from the MCM algorithm sometimes suffer from visible striping and ringing artifacts. Correcting detector gain offsets and using a Burg entropy metric in the reconstruction scheme were found to be effective in suppressing these artifacts. A variation of the destriping algorithm was used to subtract zodiacal emission.

Far infrared properties of Hickson compact groups of galaxies. I. High resolution IRAS maps and fluxes

The Far Infrared (FIR) properties of galaxies which are members of compact groups bear relevant information on the dynamical status and the physical properties of these structures. All studies published so far have been undermined by the poor sensitivity and spatial resolution of the IRAS-PSC and IRAS Sky Survey data. We used the HIRAS software available at the IRAS server at the Laboratory for Space Research in Groningen to fully exploit the redundancy of the IRAS data and to approach the theoretical diffraction limit of IRAS. Among the 97 groups which were observed by IRAS, 62 were detected in at least one band, while reliable upper limits were derived for all the others. Among the detected groups, 49 were fully or partially resolved, i.e. it was possible to discriminate which member or members emit most of the FIR light. At 60 μm, for instance, 87 individual sources were detected in 62 groups. In order to ease the comparison with data obtained at other wavelengths - and in particular in the X and radio domains - we give co-added and HIRAS maps for all the detected groups.

Millimeter and infrared observations of SGR 1806-20

We present CO(1-0) observations toward the soft gamma-ray repeater SGR 1806-20. We discuss the implications on the distance to the X-ray counterpart: AX 1805.7-2025. We also present an upper limit at λ = 1.3 mm for the thermal emission from dust and high resolution IRAS maps of the region. SGR 1806-20 is very likely associated with the H II complex W31. The G10.0-0.3 supernova remnant (SNR) could be expanding in the very low density region produced by the wind of the bright O9-B2 star recently detected.

THE ENERGY GENERATION MECHANISMS POWERING INFRARED-SELECTED GALAXIES

ABSTRACT I have applied newly available optical emission line diagnostics to two samples of infrared-luminous galaxies in a program to discriminate between possible energy generation mechanisms, i.e., active nuclei and starbursts. The first sample was composed of very faint (F(60 microns) < 180 mJy, z < 0.3) galaxies drawn from coadded IRAS scans of the North Ecliptic Pole Region (NEPR). The second sample consisted of 37 much brighter sources drawn from the IRAS Bright Galaxy Sample (BGS). Analysis of the redshift distribution of the NEPR sample revealed clustering is present on scales ~10 Mpc. In addition, a very strong cluster was identified at z=0.088 that has a surface density roughly three times greater than the Great Wall. Out of the 76 galaxies observed from the NEPR sample 17 had strong spectra suitable for the analysis, which was based on the relative intensities of forbidden and permitted emission lines. While 3 sources could be classified as AGNs and another 7 as starburst galaxies, the remaining 7 eluded classification. Longslit optical emission-line spectra, which effectively separated nuclear and disk contributions to the emission, indicated the BGS galaxies contained 7 AGNs and 24 starbursts. In a minority of 6 cases, however, the line diagnostics failed to unambiguously classify the luminosity source. Follow-up near-infrared imaging showed that the 'straddlers' have redder near-infrared colors than the other BGS galaxies. The optical spectra and near-infrared colors taken together with morphological peculiarities imply that the straddlers are composite objects harboring low-luminosity active nuclei residing within starburst disks. Finally, the optical spectrum of a high redshift IRAS galaxy was analysed. IRAS 18003+6652 is the third most distant (z=0.088) galaxy known to have been observed by IRAS and has an unusually strong emission line spectrum in combination with low-ionization absorption features.

The Seyfert II nature of the IRAS source FSC 10214+4724

view Abstract Citations (64) References (59) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Seyfert II Nature of the IRAS Source FSC 10214+4724 Elston, Richard ; McCarthy, Patrick J. ; Eisenhardt, Peter ; Dickinson, Mark ; Spinrad, Hyron ; Januzzi, Buell T. ; Maloney, Philip Abstract We have observed the rest-frame optical and UV spectra of the luminous, high redshift IRAS source FSC 10214+4724. We find the optical emission lines to be characterized by ratios similar to those found in Seyfert II galaxies. We support the conclusion of previous work that the UV emission lines are similar to those attributed to AGN rather than to star formation. The ratio Hα/Hβ >= 20 (2σ lower limit) implies substantial reddening of the narrow line region with A_V_ > 5.5, sufficient to hide a broad line region in our Hα observations. Given this large inferred reddening and the strength of the UV continuum and emission lines, we conclude (as have others) that simple screen models of reddening are not appropriate for this object. These properties are very similar to those of the infrared luminous galaxies at lower redshift, suggesting that FSC 10214+4724 is the luminous extreme of the same population. We also present H band (1.6 micron) imaging polarimetry observations and find that the rest-frame optical emission is unpolarized (P = 3.2%+/-2.0%). This deep image of the field shows FSC 10214+4724 to possess an unresolved core, with several companions located within 10" of the point source. We find it unlikely that this group of objects is physically associated with FSC 10214+4724 at z = 2.3, and we argue that their magnitudes and colors are more consistent with those expected for galaxies in a foreground group. While galaxy number counts would suggest that such a projection has a low probability of being observed randomly, a foreground group might gravitational lens the z= 2.3 source, making such random statistics inappropriate, and contribute to the large observed luminosity of FSC 10214+4724. Comparison of H band images taken on two occasions one year apart show that FSC 10214+4724 had varied by 0.16+/-0.03 mag relative to a nearby star during that time. The UV- optical emission line spectra, the bright dereddened continuum magnitude (K <= 12) of the unresolved core, its extremely large bolometric luminosity, strong UV polarization, and possible variability all suggest that FSC 10214+4724 harbors an obscured AGN. Given that we observe no spectral features attributable to star formation, it appears either that star formation in FSC 10214+4724 is more highly obscured at optical and UV wavelengths than the narrow line region of the AGN, or that the AGN (rather than star formation) dominates the large luminosity of this object. Publication: The Astronomical Journal Pub Date: March 1994 DOI: 10.1086/116905 Bibcode: 1994AJ....107..910E Keywords: Active Galactic Nuclei; Astronomical Polarimetry; Astronomical Spectroscopy; Images; Infrared Astronomy; Infrared Astronomy Satellite; Infrared Radiation; Light (Visible Radiation); Seyfert Galaxies; Ultraviolet Radiation; Astronomical Observatories; Charge Coupled Devices; Infrared Spectrometers; Morphology; Polarizers; Spectrographs; Telescopes; Astronomy; GALAXIES: SEYFERT; GALAXIES: INDIVIDUAL: FSC 10214; 4724; INFRARED: GALAXIES full text sources ADS | data products SIMBAD (5) NED (1)

High resolution IRAS observations of interacting systems in the IRAS bright galaxy sample

A sample of morphologically selected interacting galaxies has been chosen from the 60 micron flux density limited IRAS Bright Galaxy Sample [Soifer et al., ApJ, 320,238(1987)]. Using the HIRES algorithm [Aumann et al., AJ, 99, 1674(1990)] and one-dimensional coaddition, the IRAS survey data for these galaxies were analyzed and the infrared fluxes at 12, 25, 60, and 100 microns for the resolved components have been determined where possible. Of the 56 potentially resolvable interacting groups, 22 systems have been resolved yielding fluxes for a total of 51 galaxies. In about 2/3 of the resolved pairs, both galaxies are bright in the infrared. A set of isolated noninteracting galaxies with a similar distribution of blue luminosities was chosen from the IRAS Bright Galaxy Sample for comparison with the interacting galaxies. For the current sample of interacting systems resolved by IRAS the primary conclusions are as follows: (a) It is not possible to distinguish individual interacting galaxies from isolated galaxies of similar blue luminosity on the basis of infrared properties alone. Interactions of the type sampled here do not, therefore, produce any unique IR signatures in individual galaxies. The relatively large intrinsic dispersion of normal galaxy properties is likely responsible for this fact. (b) No direct correlation was found between measures of interaction strength and indicators of enhanced star formation within the resolved systems. (c) Comparison of the interacting and isolated samples indicates substantial differences between their distributions of far-infrared color ratios, luminosities, and surface brightnesses. These differences can be attributed to the expected heating of the gas rich interstellar medium due to the triggering of starbursts in the interacting galaxies. Even during the early stages of interaction spanned by these systems, tidal perturbations appear to substantially boost far-infrared indicators of star formation compared to noninteracting systems.

Submillimeter observations of radio-quiet quasars and a luminous Seyfert 1 galaxy including the first detections

Submillimeter continuum observations of six radio-quiet active galactic nuclei selected for high IRAS flux are reported, in order to test models for the infrared continuum by constraining the far-infrared/submillimeter cutoff slope. Slopes greater than the self-absorbed synchrotron cutoff of 2.5 argue against the synchrotron model and lend support to the dust model. The luminous Seyfert 1 galaxy PG 1434+590 is detected at 438 and 345 μm. Combining these detections with the IRAS 100 μm flux gives a slope of 2.53 ± 0.17

IC5063: A Merger with A Hidden Luminous Active Nucleus

Despite intense theoretical and observational effort during the past few years, two important questions in the field of active galaxies remain open and are the subject of vigorous debate.The first concerns the connection between the interaction/merger of galaxies and the generation of starburst and/or active nuclei. A large fraction of high luminosity radio galaxies (Baum et al. 1988), quasars (Hutchinga, 1987) and IRAS galaxies (Sanders et al. 1988), show the presence of a large companion or have a peculiar optical morphology which is offen interpreted as evidence of a recent merger or interaction. In Seyferts, there are also several examples of individual galaxies with clear evidence of interaction/merger (Colina et al. 1987; Fricke and Kollatschny, 1989; Macchetto et al. 1990). Also a significant fraction of low luminosity radio galaxies are associated with a system of two elliptical galaxies in interaction (Colina and Pérez-Fournon, 1990a,b).

Infrared Images of Merging Galaxies

Infrared imaging of interacting galaxies is especially interesting because their optical appearance is often so chaotic due to extinction by dust and emission from star formation regions, that it is impossible to locate the nuclei or determine the true stellar distribution. However, at near-infrared wavelengths extinction is considerably reduced, and most of the flux from galaxies originates from red giant stars that comprise the dominant stellar component by mass. Thus near infrared images offer the opportunity to study directly components of galactic structure which are otherwise inaccessible. Such images may ultimately provide the framework in which to understand the activity taking place in many of the mergers with high IRAS luminosities.

Infrared Environment of the BE Star 6 Cephei: Interaction of Stellar and Interstellar Winds

Abstract:Several arclike structures are seen on the high resolution IRAS images (processes via GEISHA system of Groningen) centred on the Be star 6 Cephei, among others an extended bow shock which indicates the rapd motion of the star and the interstellar matter relative to each other. 6 Cephei is embedded in a giant infrared-emitting shell which is thougth to be a three million year old supernova remnant, therefore in this case the presence of the bow shock around the star shows the interaction of a supernova blast wave with the stellar wind of a Be star. In this paper an attempt is made to reveal the history of the interactions of the star with its surroundings during different periods of its life which are recorded on the infrared maps. Some aspects of the formation and evolution of 6 Cephei can be inferred also from its infrared environment.

Radio identifications of IRAS point sources with B greater than 30 deg

The present radio identifications of IRAS point sources on the basis of Green Bank 1400 MHz survey maps notes that 365 hot IR sources are not detectable radio sources, and that nearly all cool high latitude IRAS sources are extragalactic. The fainter IR-source identifications encompass optically bright quasars, BL Lac objects, Seyfert galaxies, and elliptical galaxies. No IRAS sources could be identified with distant elliptical radio galaxies, so that although the radio and IR fluxes of most IRAS extragalactic sources are tightly correlated, complete samples of strong radio and IR sources are almost completely disjoint; no more than 1 percent of the IR sources are radio sources and less than 1 percent of the radio sources are IR ones. 35 references.