Related papers: A peculiar galaxy near M104

Groups are the most common association of galaxies in the Universe, found in different configuration states such as loose, compact and fossil groups. We have studied the galaxy group MKW 4s, dominated by the giant early-type galaxy NGC 4104…

Quadruple gravitational lens systems offer the possibility of measuring time delays for image pairs, microlensing effects, and extinction in distant galaxies. Observations of these systems may be used to obtain estimates of H_o and to study…

We report the discovery in our HST ACS B, V, and I images of NGC 4449 of a globular cluster (GC) which appears associated with two tails of blue stars. The cluster is massive (M~1.7x10^6 M_sun) and highly flattened (\epsilon~0.24). From the…

We present a strong-lensing (SL) analysis of the galaxy cluster MACS J1319.9+7003 ($z=0.33$, also known as Abell 1722), as part of our ongoing effort to analyze massive clusters with archival {\it HST} imaging. We spectroscopically measured…

We examine a caustic-straddling arc at $z=0.9397$ in the field of the galaxy cluster MACS J0416.1-2403 ($z=0.397$) using archival multiband HST images and show that its surface brightness exhibits anomalies that can be explained by a single…

We present deep, high angular resolution near-infrared images of the obscured Galactic Giant H II region NGC3576. Our images reach objects to ~3M_sun. We collected high signal-to-noise K-band spectra of eight of the brightest objects, some…

As galactic halos are not directly visible, there are many ambiguities regarding their composition and rotational velocity. Though most of the dark matter is non-baryonic, {\it some fraction is}, and it can be used to trace the halo…

The full stellar population of NGC 6334, one of the most spectacular regions of massive star formation in the nearby Galaxy, have not been well-sampled in past studies. We analyze here a mosaic of two Chandra X-ray Observatory images of the…

The close environment of four old Pre-Main Sequence stars has been observed thanks to the coronagraphic mode of the HST/NICMOS2 camera at lambda=1.6 micron. In the course of this program, the detection of a circumstellar annulus around HD…

We report an ultra-bright lensed submillimeter galaxy (SMG) at $z=2.0439$, {\it WISE} J132934.18+224327.3, identified as a result of a full-sky cross-correlation of the {\it AllWISE} and {\it Planck} compact source catalogs aimed to search…

We present Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph (STIS E140M) observations of the post-asymptotic giant branch star ZNG 1 in the globular cluster Messier 5 (l=3.9, b=+47.7; d=7.5 kpc, z=+5.3…

Using imaging that shows four magnitudes of main sequence stars, we have discovered that the Galactic globular cluster NGC 1851 is surrounded by a halo that is visible from the tidal radius of 700 arcsec (41 pc) to more than 4500 arcsec…

Supernova (SN) H0pe was discovered as a new transient in James Webb Space Telescope (JWST) NIRCam images of the galaxy cluster PLCK G165.7+67.0 taken as part of the "Prime Extragalactic Areas for Reionization and Lensing Science" (PEARLS)…

We present abundance measurements, based on high-resolution optical spectroscopic data obtained with the Ultraviolet and Visual Echelle Spectrograph mounted on Kueyen (Very Large Telescope UT2), for ten stars in the extended blue horizontal…

Optical spectra of SN1994W in NGC 4041 revealed the presence of a dense (N_e > 10^8 cm^-3) circumstellar shell. An observation with the ROSAT HRI detected a source, with a 0.2-2.4 keV luminosity of ~8x10^39 erg/sec, coincident with the…

Deep Effelsberg HI spectra of the one-armed, bright Virgo cluster spiral galaxy NGC 4254 are presented.Five different positions were observed in the 21 cm HI line with the Effelsberg 100-m telescope: one in the center and 4 located one HPBW…

VLBI observations at 5 GHz have revealed that supernova 1979C, in the galaxy M100 in the Virgo cluster, has shell structure. The shell is approximately circular with the 50% contour deviating from a circle by an rms of no more than 8% of…

The multiple images observed in galaxy cluster Abell 1689 provide strong constraints not only on the mass distribution of the cluster but also on the ensemble properties of the cluster galaxies. Using parametric strong lensing models for…

In this Research Note we present a serendipitous discovery of the transient CGS2004A (AT2004iu) in an image collected by the Carnegie-Irvine Galaxy Survey of the Scd: galaxy NGC 1892, which we determine is most likely to have been a type…

We are performing a systematic study of the properties of early-type galaxies in the mid infrared spectral region with the Spitzer Space Telescope. We present here high S/N Spitzer IRS spectra of 17 Virgo early-type galaxies. Thirteen…