Search Publications
M31 PAndromeda Cepheid Sample Observed in Four HST Bands
Bender, Ralf; Seitz, Stella; Hopp, Ulrich +5 more
Using the M31 PAndromeda Cepheid sample and the HST PHAT data, we obtain the largest Cepheid sample in M31 with HST data in four bands. For our analysis we consider three samples: a very homogeneous sample of Cepheids based on the PAndromeda data, the mean magnitude corrected PAndromeda sample and a sample complementing the PAndromeda sample with …
NOEMA Observations of a Molecular Cloud in the Low-metallicity Galaxy Kiso 5639
Elmegreen, Bruce G.; Rubio, Monica; Muñoz-Tuñón, Casiana +4 more
A giant star-forming region in a metal-poor dwarf galaxy has been observed in optical lines with the 10 m Gran Telescopio Canarias (GTC) and in the emission line of CO(1-0) with the Northern Extended Millimeter Array (NOEMA) mm-wave interferometer. The metallicity was determined to be 12+{log}({{O}}/{{H}})=7.83+/- 0.09, from which we estimate a co…
Quest for the Donor Star in the Magnetic Precataclysmic Variable V1082 Sgr
González, J. F.; Zharikov, S.; Tovmassian, G. +3 more
We obtained high-resolution spectra and multicolor photometry of V1082 Sgr to study the donor star in this 20.8 hr orbital period binary, which is assumed to be a detached system. We measured the rotational velocity (v\sin i=26.5+/- 2.0 km s-1), which, coupled with the constraints on the white dwarf mass from the X-ray spectroscopy, lea…
The Embedded Ring-like Feature and Star Formation Activities in G35.673-00.847
Dewangan, L. K.; Ojha, D. K.; Devaraj, R.
We present a multiwavelength study to probe the star formation (SF) process in the molecular cloud linked with the G35.673-00.847 site (hereafter MCG35.6), which is traced in a velocity range of 53-62 km s-1. Multiwavelength images reveal a semi-ring-like feature (associated with ionized gas emission) and an embedded face-on ring-like f…
New Insights into the Formation of the Blue Main Sequence in NGC 1850
Milone, Antonino P.; Deng, Licai; de Grijs, Richard +2 more
Recent discoveries of bimodal main sequences (MSs) associated with young clusters (with ages ≲1 Gyr) in the Magellanic Clouds have drawn a lot of attention. One of the prevailing formation scenarios attributes these split MSs to a bimodal distribution in stellar rotation rates, with most stars belonging to a rapidly rotating population. In this sc…
A Study of Two Dwarf Irregular Galaxies with Asymmetrical Star Formation Distributions
Gouliermis, Dimitrios A.; Grebel, Eva K.; Calzetti, Daniela +23 more
Two dwarf irregular galaxies, DDO 187 and NGC 3738, exhibit a striking pattern of star formation: intense star formation is taking place in a large region occupying roughly half of the inner part of the optical galaxy. We use data on the H I distribution and kinematics and stellar images and colors to examine the properties of the environment in t…
Discovery of X-Rays from the Old and Faint Pulsar J1154-6250
Mereghetti, Sandro; Igoshev, Andrei P.; Popov, Sergei B. +4 more
We report on the first X-ray observation of the 0.28 s isolated radio pulsar PSR J1154-6250 obtained with the XMM-Newton observatory in 2018 February. A point-like source is firmly detected at a position consistent with that of PSR J1154-6250. The two closest stars are outside the 3σ confidence limits of the source position and thus unlikely to be…
Revealing the Host Galaxy of a Quasar 2175 Å Dust Absorber at z = 2.12
Ge, Jian; Prochaska, J. Xavier; Brammer, Gabriel +2 more
We report the first detection of the host galaxy of a strong 2175 Å dust absorber at z = 2.12 toward the background quasar SDSS J121143.42+083349.7 using Hubble Space Telescope/Wide Field Camera 3 (HST/WFC3) IR F140W direct imaging and G141 grism spectroscopy. The spectroscopically confirmed host galaxy is located at a small impact parameter of ∼5…
HST STIS UV Spectroscopic Observations of the Protoplanetary Nebula Hen3-1475
Gómez de Castro, Ana I.; Toalá, Jesús A.; Fang, Xuan +1 more
We present UV spectra of the protoplanetary nebula (pPN) Hen 3-1475 obtained with the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST). Our deep, low-dispersion spectroscopy enables monochromatic imaging of Hen 3-1475 in ultraviolet (UV) nebular emission lines, the first of such attempt ever made for a pPN. The…
NGC 6744: A Nearby Milky Way Twin with a Very Low-luminosity AGN
Steiner, J. E.; Menezes, R. B.; da Silva, Patrícia
NGC 6744 is the nearest and brightest south-hemisphere galaxy with a morphological type similar to that of the Milky Way. Using data obtained with the Integral Field Unit of the Gemini South Multi-Object Spectrograph, we found that this galaxy has a nucleus with LINER (Low Ionization Nuclear Emission Line Region) surrounded by three line emitting …