Using the Spitzer Space Telescope, we have obtained 3.6--24 micron photometry of 38 radio galaxies and 24 quasars from the 3CR catalog at redshift 1<z<2.5. This 178 MHz-selected sample is unbiased with respect to orientation and therefore suited to study orientation-dependent effects in the most powerful active galactic nuclei (AGN). Quasar and radio galaxy subsamples matched in isotropic radio luminosity are compared. The quasars all have similar spectral energy distributions (SEDs), nearly constant in nu F_nu through the rest 1.6-10 micron range, consistent with a centrally heated dust distribution which outshines the host galaxy contribution. The radio galaxy SEDs show larger dispersion, but the mean radio galaxy SED declines from rest 1.6 to 3 micron and then rises from 3 to 8 micron. The radio galaxies are on average a factor 3-10 less luminous in this spectral range than the quasars. These characteristics are consistent with composite emission from a heavily reddened AGN plus starlight from the host galaxy. The mid-infrared colors and radio to mid-infrared spectral slopes of individual galaxies are also consistent with this picture. Individual galaxies show different amounts of extinction and host galaxy starlight, consistent with the orientation-dependent unified scheme.
Near-infrared photometry of transiting extrasolar planets can be of great scientific value. It is however not straightforward to reach the necessary millimagnitude precision. Here we report on our attempts to observe transits and secondary eclipses of several extrasolar planets at 2.2 micron. Best results have been obtained on OGLE-TR-113b using the SOFI near-infrared camera on ESO's New Technology Telescope. Its K-band transit shows a remarkably flat bottom indicating low stellar limb darkening. Secondary eclipse photometry has resulted in a formal 3 sigma detection, but residual systematic e…
We present optical and near-infrared photometry of 45 clusters of galaxies at 0.1 < z < 1.3. Galaxy catalogs in each cluster were defined at the longest wavelenth available, generally the K-band, down to approximately two magnitudes below M*. We include finding chart images of the band used for catalog definition. The photometry has been used in previously published papers to examine the origin and evolution of galaxies in distant clusters.
We present near infrared photometry of the Type Ia supernova 1999ee; also, optical and infrared photometry of the Type Ia SNe 2000bh, 2000ca, and 2001ba. For SNe 1999ee and 2000bh we present the first-ever SN photometry at 1.035 microns (the Y-band). We present K-corrections which transform the infrared photometry in the observer's frame to the supernova rest frame. Using our infrared K-corrections and stretch factors derived from optical photometry, we construct JHK templates which can be used to determine the apparent magnitudes at maximum if one has some data in the window -12 to +10 d with…
We present photometry in the J and K near-infrared bands for two regions centered on the young open clusters NGC 1893 and Berkeley 86. We study 700 stars down to K = 17 in the field of NGC 1893, and about 2000 stars in the field of Berkeley 86 down to K$\sim$ 16.5, for which near-infrared photometry was insofar not available. Coupling J-K data with UBV photometry taken from literature, we produce reddening corrected colour-magnitude diagrams. We find that our data are consistent with previous determinations: the clusters are roughly coeval with an age between 4 and 6 million years. The mean re…
Two days of observations were conducted at the Palomar Observatory during the nights of 25 and 26 February 1997 with the Hale telescope, in order to search for rapid variability in the near-infrared (NIR) bands J, H, Ks for a selection of eight blazars. With the possible exception of PKS 1156+295, no intraday or day-to-day variability was observed during these two nights. However, for these eight blazars, we have measured the NIR spectral indices.
We present JHK photometry and spectroscopy of RX J0019.8+2156. The spectrum appears to be dominated by the accretion disc to at least 2.4 microns, over any other source of emission. We find Paschen, Brackett and HeII lines strongly in emission, but no HeI. There are satellite lines approximately 850km/s either side of the strongest, unblended hydrogen lines. These satellite lines may be the spectral signature of jets from the accretion disc.
We present JHK-band near-infrared photometry of star clusters in the dwarf irregular galaxy IC 5152. After excluding possible foreground stars, a number of candidate star clusters are identified in the near-infrared images of IC 5152, which include young populations. Especially, five young star clusters are identified in the (J-H, H-K) two color diagram and the total extinction values toward these clusters are estimated to be A_V =2 - 6 from the comparison with the theoretical values given by the Leitherer et al. (1999)'s theoretical star cluster model.
A preliminary analysis of the data from the MSX space infrared satellite, seems to confirm that the [8.8]-[12.5] micron color index is well correlated with the mass-loss rates in carbon stars of our Galaxy. The extension of this mid-infrared observation criterion to the Magellanic Clouds, with a small-size telescope, able to perform a continuous survey from Dome-C on the Antarctic Plateau, could be crucial to trace the local AGB population and evolution.
We present broad-band infrared photometry for 52 late-type supergiants in the young Magellanic Clouds clusters NGC 330, NGC 1818, NGC 2004 and NGC 2100. Standard models are seen to differ in the temperature they predict for the red supergiant population on the order of 300K. It appears that these differences most probably due to the calibration of the mixing-length parameter, $α_{P}$, in the outermost layers of the stellar envelope. Due to the apparent model dependent nature of $α_{P}$ we do not quantitatively compare $α_{P}$ between models. Qualitatively, we find that $α_{P}$ decreases with i…
We present several corrections for point source photometry to be applied to data from the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. These corrections are necessary because of characteristics of the IRAC arrays and optics and the way the instrument is calibrated in-flight. When these corrections are applied, it is possible to achieve a ~2% relative photometric accuracy for sources of adequate signal to noise in an IRAC image.
Infrared to millimetre spectral energy distributions have been obtained for 41 bright ultra-luminous infrared galaxies. The observations were carried out with ISOPHOT between 10 and 200 micron and supplemented for 16 sources with SCUBA at 450 and 850 micron and with SEST at 1.3 mm. In addition, seven sources were observed at 1.2 and 2.2 $μ$m with the 2.2 m telescope on Calar Alto. These new SEDs represent the most complete set of infrared photometric templates obtained so far on ULIRGs in the local universe.
We present high-quality near-Infrared photometry of four Bulge metal-rich globular clusters, namely: NGC 6304, NGC 6569, NGC 6637 and NGC 6638. By using the observed Colour-Magnitude Diagrams we derived a photometric estimates of the cluster reddening and distance. We performed a detailed analysis of the Red Giant Branch, presenting a complete description of morphologic parameters and evolutionary features (Bump and Tip). Photometric estimates of the cluster metallicity have been obtained by using the updated set of relations (published by our group) linking the metal abundance to a variety of…
We present BVRI photometry of the Type Ia supernovae 1999da, 1999dk, 1999gp, 2000bk, and 2000ce, plus infrared photometry of three of these. These objects exhibit the full range of decline rates of Type Ia supernovae. Combined optical and infrared data show that families of V - infrared color curves can be used to derive the host extinction (A_V) of these objects. Existing data do not yet allow us to construct these loci for all color indices and supernova decline rates, but the V-K color evolution is sufficiently uniform that it allows the determination of host extinction over a wide range of…
We present JHKs photometry of 10 Jovian and 4 Saturnian irregular satellites, taken with the Near-InfraRed Imager (NIRI) at the 8-m Gemini North Observatory on Mauna Kea, Hawaii. The observed objects have near-infrared colors consistent with C, P and D-type asteroids, although J XII Ananke and S IX Phoebe show weak indications of possible water features in the H filter. The four members of the Himalia-family have similar near-infrared colors, as do the two members of the Gallic family, S XX Paaliaq and S XXIX Siarnaq. From low resolution normalized reflectance spectra based on the broadband co…
We present JHKL' photometry of a complete sample of steep-spectrum radio-loud quasars from the revised 3CR catalogue in the redshift range 0.65 < z < 1.20. After correcting for contributions from emission lines and the host galaxies, we investigate their spectral energy distributions (SEDs) around 1 micron. About 75% of the quasars are tightly grouped in the plane of optical spectral index, alpha_lo, versus near-infrared spectral index, alpha_hi, with the median value of alpha_lo close to the canonical value, and the median alpha_hi slightly flatter. We conclude that the fraction of moderately…
We present brief review of two probable physical mechanisms that can explain the results of photometric and spectropolarimetric observations of magnetic white dwarfs: vacuum polarization effect into a strong magnetic field and, so-called, magnetic collision induced absorption (magnetic CIA). Both mechanisms provide observed rotation of polarization ellipse and suppression of spectral energy distributions. The results of spectropolarimetric observations of magnetic white dwarfs made at Russian BTA-6m and the results of the near infrared photometric observations with Russian-Italian AZT-24 teles…
The Infrared spectral region is a rich one for variable star work, especially of cooler stars, but it has been hard to do IR photometry because of high, variable background, and specialized telescopic equipment that is usually required to obtain meaningful data. Typically telescopes with IR detectors have been at high elevations, to minimize water vapor absorption. Nearly all the filters produced for astronomical work at observatories around the world have not been optimized for use at anything other than the highest and driest of observatories. This has made it difficult for amateur astronome…
Near-infrared photometry of planetary nebulae (PNe) allows the classification of those objects. We present the largest homogeneous sample so far, obtained with the Deep Near Infrared Southern Sky Survey (DENIS).
We present time-resolved near-infrared (J and H) photometry of the extreme Kuiper belt object (136108) Haumea (formerly 2003 EL61) taken to further investigate rotational variability of this object. The new data show that the near-infrared peak-to-peak photometric range is similar to the value at visible wavelengths, Δm_R = 0.30+/-0.02 mag. Detailed analysis of the new and previous data reveals subtle visible/near-infrared color variations across the surface of Haumea. The color variations are spatially correlated with a previously identified surface region, redder in B-R and darker than the m…
We report the design, operation, and performance of a next generation high-speed data acquisition system for multi-channel infrared and optical photometry based on the modern technologies of Field Programmable Gate Arrays, the Peripheral Component Interconnect bus, and the Global Positioning System. This system allows either direct recording of photon arrival times or binned photon counting with time resolution up to 1-$μ$s precision in Universal Time, as well as real-time data monitoring and analysis. The system also allows simultaneous recording of multi-channel observations with very flexib…
We discuss the possibilities of the BaSeL models in its lowest temperature boundary (Teff ~ 2500 K for cool giants) to provide the Teff of AGB stars. We present the first step of our work, by comparing our predictions for the AGB star R Fornacis with the results of Lorenz-Martins & Lefevre (1994) based on the dust spectral energy distribution.
We investigate the intermediate-age asymptotic giant branch stellar population of two Local Group dwarf irregular galaxies to characterize their carbon star population in near-infrared (IR). Our work is based on J and K-band SOFI near-IR photometry complemented with optical ground based and HST photometry. We show that near-IR photometry is a very powerful tool for carbon star detection. We recovered two out of three previously-known carbon stars in DDO 210 and discovered six additional objects in this galaxy which have optical and near-IR colors consistent with carbon giants. This brings the …
We present photometrically calibrated images and surface photometry in the B, V, R, J, H, and K-bands of 25, and in the g, r, and K-bands of 5 nearby bright (Bo_T<12.5 mag) spiral galaxies with inclinations between 30-65 degrees spanning the Hubble Sequence from Sa to Scd. Data are from The Ohio State University Bright Spiral Galaxy Survey, the Two Micron All Sky Survey, and the Sloan Digital Sky Survey Second Data Release. Radial surface brightness profiles are extracted, and integrated magnitudes are measured from the profiles. Axis ratios, position angles, and scale lengths are measured fro…
We present arcsecond-scale mid-ir photometry (in the 10.5 micron N band and at 24.8 microns), and low resolution spectra in the N band (R~100) of a candidate high mass protostellar object (HMPO) in IRAS 18151-1208 and of two HMPO candidates in IRAS 20343+4129, IRS 1 and IRS 3. In addition we present high resolution mid-ir spectra (R~80000) of the two HMPO candidates in IRAS 20343+4129. These data are fitted with simple models to estimate the masses of gas and dust associated with the mid-ir emitting clumps, the column densities of overlying absorbing dust and gas, the luminosities of the HMPO …
We present a preliminary report on the first deep infrared photometry of 2MASS GC01 and 2MASS GC02 (GC01 and GC02 hereafter) - new Galactic globular cluster (GC) candidates, discovered by the 2MASS. They both appear to be genuine disk GCs though highly obscured. The location of the two GCs suggests that they are metal rich - [Fe/H]~-0.5. We estimated their distance and reddening using the K_s-band brightness of the red giant branch (RGB) bump, and J-K_s color of the RGB at M_K=-3 mag: D=3.1+/-0.5, 3.9+/-0.6 kpc, and A_V=20.9+/-0.7, 17.2+/-1.2 mag, for GC01 and GC02 respectively. Variation in t…
We make use of new near and mid-IR photometry of the Pleiades cluster in order to help identify proposed cluster members. We also use the new photometry with previously published photometry to define the single-star main sequence locus at the age of the Pleiades in a variety of color-magnitude planes. The new near and mid-IR photometry extend effectively two magnitudes deeper than the 2MASS All-Sky Point Source catalog, and hence allow us to select a new set of candidate very low mass and sub-stellar mass members of the Pleiades in the central square degree of the cluster. We identify 42 new c…
We present here mid-infrared images of seven sites of water maser emission thought to be associated with the hot molecular core (HMC) phase of massive star formation. Observations were obtained at the NASA InfraRed Telescope Facility 3-m, the Gemini 8-m, and Keck II 10-m telescopes. We have detected mid-infrared sources at the locations of two HMC candidates, G11.94-0.62 and G45.07-0.13. We observed G19.61-0.23 and G34.26+0.15, each of which have HMCs previously detected in the mid-infrared. We did not detect mid-infrared emission from either HMC source, and we place new upper limits on the mi…
We present an RI photometric survey covering an area of 430 arcmin^2 around the multiple star Sigma Orionis. The observations were conducted with the 0.8 m IAC-80 Telescope at the Teide Observatory. The survey limiting R and I magnitudes are 22.5 and 21, and completeness magnitudes 21 and 20, respectively. We have selected 53 candidates from the I vs. R-I colour-magnitude diagram (I=14-20) that follow the previously known photometric sequence of the cluster. Adopting an age of 2-4 Myr for the cluster, we find that these objects span a mass range from 0.35 Msol to 0.015 Msol. We have performed …
From near-infrared, narrow-band photometry of 256 oxygen-rich Mira variables we obtain evidence about the loops that these stars follow in colour-colour diagrams. We also find a phase lag between indices related to molecular band-strength of titanium oxide and vanadium oxide. We compute colours for normal M-giants and Miras using hydrostatic and hydrodynamic model atmospheres and very extensive up-to-date line lists. Normal M-giants colours are well reproduced, reaching a high quantitative agreement with observations for spectral types earlier than M7. The out-of-phase variations of the variou…
We broadly discuss mid-infrared spectroscopy and detail our new high spectral resolution instrument, the Texas Echelon-cross-Echelle Spectrograph (TEXES).
We present well sampled optical (UBVRI) and infrared (JHK) light curves of the nearby (~18.0 Mpc) Type Ia supernova SN 2001el, from 11 days before to 142 days after the time of B-band maximum. The data represent one of the best sets of optical and infrared photometry ever obtained for a Type Ia supernova. Based on synthetic photometry using optical spectra of SN 2001el and optical and infrared spectra of SN 1999ee, we were able to devise filter corrections for the BVJHK photometry of SN 2001el which to some extent resolve systematic differences between SN 2001el datasets obtained with differen…
We have observed 14 nearby (z<0.16) Ultraluminous Infrared Galaxies (ULIRGs) with Spitzer at 3.6-24 microns. The underlying host galaxies are well-detected, in addition to the luminous nuclear cores. While the spatial resolution of Spitzer is poor, the great sensitivity of the data reveals the underlying galaxy merger remnant, and provides the first look at off-nuclear mid-infrared activity.
The mid-infrared emission at the center of IRAS 21026+4104 is not that of a simple compact source, as one would expect from an isolated high mass protostellar object. Furthermore the central thermal infrared emission does not appear to be coming directly from a circumstellar disk as has been recently hypothesized from near-infrared observations. The mid-infrared structure is complex, but with the help of multiple wavelength information two plausible scenarios to explain the emission in the region are advanced. The first is that there is a tight cluster of young stellar objects here. The second…
We present infra-red (JHK) photometry of 52 isolated Be stars of spectral types O9--B9 and luminosity classes III--V. We describe a new method of reduction, enabling separation of interstellar reddening and circumstellar excess. Using this technique we find that the disc emission makes a maximum contribution to the optical (B-V) colour of a few tenths of a magnitude. We find strong correlations between a range of emission lines (Hα, Brγ, Br11, and Br18) from the Be stars' discs, and the circumstellar continuum excesses. We also find that stellar rotation and disc excess are correlated.
Near-infrared photometry (JHKL'M) was obtained for 78 semiregular variables (SRVs) in field #3 of the Palomar-Groningen survey (PG3, l=0, b=-10). Together with a sample of Miras in this field a comparison is made with a sample of field SRVs and Miras. The PG3 SRVs form a sequence (period-luminosity & period-colour) with the PG3 Miras, in which the SRVs are the short period extension to the Miras. The field and PG3 Miras follow the same P/(J--K)o relation, while this is not the case for the field and PG3 SRVs. Both the PG3 SRVs and Miras follow the SgrI period-luminosity relation adopted from G…
We present a compilation and study of DENIS, 2MASS, ISOGAL, MSX and IRAS 1--25 micron photometry for a sample of 441 late-type stars in the inner Galaxy, which we previously searched for 86 GHz SiO maser emission (Messineo et al.2002). The comparison of the DENIS and 2MASS J and Ks magnitudes shows that most of the SiO targets are indeed variable stars. The MSX colours and the IRAS [12]-[25] colour of our SiO targets are consistent with those of Mira type stars with dust silicate feature at 9.7 micron feature in emission, indicating only a moderate mass-loss rate.
We present mid-infrared maps and preliminary analysis for 61 galaxies observed with the ISOCAM instrument aboard the Infrared Space Observatory. Many of the general features of galaxies observed at optical wavelengths---spiral arms, disks, rings, and bright knots of emission---are also seen in the mid-infrared, except the prominent optical bulges are absent at 6.75 and 15 microns. In addition, the maps are quite similar at 6.75 and 15 microns, except for a few cases where a central starburst leads to lower 6.75/15 ratios in the inner region. We also present infrared flux densities and mid-infr…
Observations of the planetary nebulae NGC6302, NGC6543 and NGC7027 by the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory (ISO) have been used to determine rest wavelengths of spectral lines. We report on improved accuracies for wavelengths of 7 mid-infrared ionic fine structure lines.
We report mid-infrared observations of several luminous infrared galaxies (LIGs) carried out with the Infrared Space Observatory. Our sample was chosen to represent different phases of a merger sequence of galaxy-galaxy interaction with special emphasis on early/intermediate stages of merging. The mid-infrared emission of these LIGs shows extended structures for the early and intermediate mergers, indicating that most of the mid-infrared luminosities are not from a central active galactic nucleus (AGN). Both the infrared hardness (indicated by the IRAS 12, 25, and 60 $\micron$ flux density rat…
The young massive stellar object G35.20-0.74 was observed in the mid-infrared using T-ReCS on Gemini South. Previous observations have shown that the near infrared emission has a fan-like morphology that is consistent with emission from the northern lobe of a bipolar radio jet known to be associated with this source. Mid-infrared observations presented in this paper show a monopolar jet-like morphology as well, and it is argued that the mid-infrared emission observed is dominated by thermal continuum emission from dust. The mid-infrared emission nearest the central stellar source is believed t…
Spitzer IRAC mid-infrared photometry is presented for the globular cluster (GC) systems of the NGC 5128 ("Centaurus A") and NGC 4594 ("Sombrero") galaxies. Existing optical photometric and spectroscopic are combined with this new data in a comprehensive optical to mid-IR colour catalogue of 260 GCs. Empirical colour-metallicity relationships are derived for all optical to mid-IR colour combinations. These colours prove to be very effective quantities to test the photometric predictions of simple stellar population (SSP) models. In general, four SSP models show larger discrepancies between each…
We investigated with MIDI the extension of dusty mid-infrared excess sources (IRS 1W, IRS 10W, IRS 2, IRS 8) in immediate vicinity to the black hole (BH) at the GC. We derive 3$σ$ upper limits of the correlated fluxes of our target sources which give direct constraints on the size of the emitting regions. Most probably the emission originates from bow shocks generated by windy stars ploughing through the dense matter of the Northern MiniSpiral.
This article presents a review of all high-resolution ground-based mid-infrared observations of high mass protostellar objects (HMPOs) to date. An introduction to the characteristics of HMPOs and their relationship to the hot molecular core phase of massive star formation is outlined. I explain why observations in the mid-infrared of these types of sources are important, and in particular why high-resolution observations are needed. A summary is given of the earliest mid-infrared detections of HMPOs, followed by a detailed account of the most recent observations.
We present JHK surface photometry of 15 highly inclined, late-type (Sab-Sc) spirals and investigate the quantitative effects of dust extinction. Using the (J - H, H - K) two-color diagram, we compare the color changes along the minor axis of each galaxy to the predictions from different models of radiative transfer. Models in which scattering effects are significant and those with more than a small fraction of the light sources located near the edge of the dust distribution do not produce enough extinction to explain the observed color gradients across disk absorption features. The optical dep…
Using the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope, we have obtained rest frame mid-infrared spectroscopy of two bright submillimeter galaxies. SMMJ02399-0136 at z=2.81 shows a superposition of PAH emission features and a mid-infrared continuum, indicating significant and roughly equal contributions to its bolometric luminosity from star formation and from a Compton-thick AGN. We derive a new redshift of z=2.80 for MMJ154127+6616 from the IRS spectrum and find this object is dominated by starburst PAH emission. The rest frame mid- to far-infrared spectral energy distrib…
Fluxes are measured for the DA white dwarf plus brown dwarf pair GD 1400 with the Infrared Array Camera on the {\em Spitzer Space Telescope}. GD 1400 displays an infrared excess over the entire $3-8μ$m region consistent with the presence of a mid- to late-type L dwarf companion. A discussion is given regarding current knowledge of this unique system.
We present extensive and accurate photometry in the near-infrared H band of a complete sample of objects in an area of about 400 arcmin2 toward the Coma cluster of galaxies. The sample, including about 300 objects, is complete down to H~17 mag, the exact value depending on the type of magnitude (isophotal, aperture, Kron) and the particular region studied. This is six magnitudes below the characteristic magnitude of galaxies, well into the dwarfs' regime at the distance of the Coma cluster. For each object (star or galaxy) we provide aperture magnitudes computed within five different apertures…
We present an analysis of brown dwarf model spectra in the mid-infrared spectral region (5 - 20 microns), in anticipation of data obtained with the Space Infrared Telescope Facility. The mid-infrared spectra of brown dwarfs are in several ways simpler than those in the near-infrared and yet provide powerful diagnostics of brown dwarf atmospheric physics and chemistry, especially when combined with ground-based data. We discuss the possibility of detection of new molecular species and of the silicate cloud, predict strong observational diagnostics for non-equilibrium chemistry between CO and CH…
We have identified two late M dwarfs within 10 parsecs of the Sun, by cross-correlating the Luyten NLTT catalogue of stars with proper motions larger than 0.18 arcsec/yr, with objects lacking optical identification in the 2MASS data base. The 2MASS photometry was then combined with improved optical photometry obtained from the SuperCOSMOS Sky Surveys. The two objects (LP775-31 and LP655-48) have extremely red optical-to-infrared colours ((R-K)~7) and very bright infrared magnitudes (K_s<10): follow-up optical spectroscopy with the ESO 3.6-m telescope gave spectral types of M8.0 and M7.5 dwarfs…
We present JHK photometry of Palomar 6. Our photometric measurements range from the RGB-tip to 2 mag below the RHB and our CMDs show that Palomar~6 appears to have a well-defined RHB population. The distance modulus and interstellar reddening of the cluster are estimated by comparing the magnitude and color of Palomar 6 RHB stars with respect to those of 47 Tuc. We obtain (m-M)_0 = 14.28 mag and E(B-V) = 1.30 mag for the cluster and our study suggests that Palomar~6 is clearly located in the Galaxy's central regions. We also discuss the metallicity of the cluster using the slope of the RGB. We…
Galaxy source counts that simultaneously fit the deep mid-infrared surveys at 24 microns and 15 microns made by the Spitzer Space Telescope and the Infrared Space Observatory (ISO) respectively are presented for two phenomenological models. The models are based on starburst and luminous infrared galaxy dominated populations. Both models produce excellent fits to the counts in both wavebands and provide an explanation for the high redshift population seen in the longer Spitzer 24 micron band supporting the hypothesis that they are luminous-ultraluminous infrared galaxies at z=2-3, being the mid…
We present rest frame mid-infrared spectroscopy of a sample of 13 submillimeter galaxies, obtained using the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope. The sample includes exclusively bright objects from blank fields and cluster lens assisted surveys that have accurate interferometric positions. We find that the majority of spectra are well fitted by a starburst template or by the superposition of PAH emission features and a weak mid-infrared continuum, the latter a tracer of Active Galactic Nuclei (including Compton-thick ones). We obtain mid-infrared spectroscopic reds…
We present deep near-infrared images of the Antennae galaxies, taken with the Palomar Wide-Field Infrared Camera WIRC. The images cover a 4.33' x 4.33' (24.7kpc x 24.7kpc) area around the galaxy interaction zone. We derive J and K_s band photometric fluxes for 172 infrared star clusters, and discuss details of the two galactic nuclei and the overlap region. We also discuss the properties of a subset of 27 sources which have been detected with WIRC, HST and the VLA. The sources in common are young clusters of less than 10 Myr, which show no correlation between their infrared colors and 6 cm rad…
We present near-infrared (JKs) time series data of the Large Magellanic Cloud (LMC) cluster Reticulum. The observing strategy and data reduction (DAOPHOTII/ALLFRAME) allowed us to reach a photometry accuracy of the order of 0.02 mag at limiting magnitudes typical of RR Lyrae stars. We are interested in Reticulum, since it hosts a sizable sample of RR Lyrae (32), and therefore the use of the K-band Period-Luminosity-Metallicity (PLZ_K) relation will allow us to supply an accurate LMC distance evaluation. The main advantages in using this method is that it is marginally affected by off-ZAHB evol…
A mid-infrared atlas of part of the Galactic plane ($75^\circ < l < 148^\circ, b = \pm6^\circ$) has been constructed using HIRES processed infrared data to provide a mid-infrared data set for the Canadian Galactic Plane Survey (CGPS). The addition of this data set to the CGPS will enable the study of the emission from the smallest components of interstellar dust at an angular resolution comparable to that of the radio, millimetre, and far-infrared data in the CGPS. The Mid-Infrared Galaxy Atlas (MIGA) is a mid-infrared (12 $μ$m and 25 $μ$m) counterpart to the far-infrared IRAS Galaxy Atlas (IG…
Mid-infrared (10-25 \micron) imaging of the protostellar binary system L1448N-IRS3(A,B) is presented. Only one source, IRS3(A), was detected at mid-infrared wavelengths -- all of the mid-infrared emission from IRS3(A,B) emanates from IRS3(A). The mid-infrared luminosity of IRS3(A) is $L_{midir} = 1.3(\frac{d}{300\rm{pc}})^2 L_\sun$, which yields a central source mass, depending on the mass infall rate, of $M_* = 0.2 M_\sun \frac{10^{-6}M_\sun yr^{-1}}{\dot M}$. The envelope mass surrounding IRS3(A) is $\sim 0.15 M_\sun$, suggesting that the central source and the envelope are of comparable mas…
<<>> Among the components of the infrared and submillimetre sky background, the closest layer is the thermal emission of dust particles and minor bodies in the Solar System. This contribution is especially important for current and future infrared and submillimetre space instruments --like those of Spitzer, Akari and Herschel -- and must be characterised by a reliable statistical model. <<>> We describe the impact of the thermal emission of main belt asteroids on the 5...1000um photometry and source counts, for the current and future spaceborne and ground-based instruments, in general, as well…
We present near-infrared J- and K-band photometry of 77 Cepheid variables in the Local Group galaxy NGC 3109. Combining our data with the previously published optical V- and I-band photometry of Cepheids in this galaxy we derive an accurate distance and interstellar reddening to NGC 3109. Adopting a distance modulus of 18.5 mag for the Large Magellanic Cloud, we obtain a true distance modulus to NGC 3109 of (m-M)_0 = 25.571 +- 0.024 mag (random error), corresponding to a distance of 1.30 +- 0.02 Mpc. The systematic uncertainty on this value (apart from the adopted LMC distance) is of the order…
We present near infrared JHK photometry for the central area of the irregular dwarf galaxy IC10. Comparing the red supergiants of IC10 and IC1613 we have determined the reddening of E(B-V)=1.05+-0.10 and the dereddened distance modulus (m-M)_0=23.86+-0.12 mag of Population I stars in IC10. Detection of six Brgamma emission structures clearly outline two star forming regions in the central area of IC10. There is no H_2 emissions down to 4.65 $10^{-16}$ $\rm erg s^{-1} cm^{-2} arcsec^{-2}$ indicating that the dominant excitation mechanism of the molecular gas is from UV radiation from hot young …
