We describe the far-infrared (far-IR; rest-frame 8–1000μm) properties of a sample of 443 Hα-selected star-forming galaxies in the COSMOS and UDS fields detected by the HiZELS imaging survey. Sources are identified using narrow-band filters in combination with broad-band photometry to uniformly select Hα (and [O ii] if available) emitters in a narrow redshift slice at z = 1.47 ± 0.02. We use a s...

A detailed analysis on the physical conditions of the Interstellar Medium in the main body of the Local Group dwarf irregular galaxy IC 10 is carried out using long-slit spectroscopy. Maps of the excitation, the Hα flux, [NII]/Hα and [SII]/Hα are presented. The Diffuse Ionized Gas inside the galaxy is studied. We found that the spectral characteristics are not similar to those for spiral galaxi...

“Elementary bursts” refer to fine time structures on scales of tens of milli-second to a few seconds in flare radiations. In this paper, we investigate temporal and spatial properties of elementary bursts by exploiting high-cadence Hα (100 ms) and hard X-ray (125 – 500 ms) observations of an impulsive flare on March 16, 2000. We find that the time scale of 2 – 3 s is likely an upper limit of th...

We obtained medium-resolution spectra of the bonafide brown dwarf Cha Hα 1, the five brown dwarf candidates Cha Hα 2 to 6, two additional late M-type brown dwarf candidates, all originally selected by Hα emission, and four previously known T Tauri stars, all located in Chamaeleon I. The spectral types of our targets range down to M8. We show their spectra and also list their IJK magnitudes from...

High quality 4500–6800 Å spectropolarimetric observations of the Circinus galaxy are reported. These show polarized and relatively broad (FWHM∼3300 km/s) Hα (as well as marginal Hβ) arising from a <3′′ (<60 pc) region centered on the nucleus and coincident with the the peak of the narrow line region. Broad Hα might also be present ∼8′′ (160 pc) SE from the nucleus and close to the dust lane, bu...

In 2014, Kielkopf and Allard (KA) performed a benchmark experiment where they measured the Full Width at Half Maximum (FWHM) of the Hα line at the electron densities Ne by two orders of magnitude greater than the corresponding previous benchmark experiments, namely up to Ne = 1.4 × 10 20 cm-3. No theoretical calculations of the FWHM of the Hα line existed in this range of Ne. In the present pap...

We report the discovery of an extremely broad Hα emission line in the LINER nucleus of NGC 4579. From ground-based observations, the galaxy was previously known to contain a Type 1 nucleus with a broad Hα line of FWHM ≈ 2300 km s and FWZI ≈ 5000 km s. New spectra obtained with the Hubble Space Telescope (HST ) and a 0. 2-wide slit reveal an Hα component with a FWZI of ∼ 18,000 km s. The line is...

We present high spatial resolution observations of the blue compact dwarf galaxy IZW 18 performed in the Hα line with a scanning Fabry-Perot interferometer at the CFH telescope. Morphological structure of the galaxy in Hα and in the red continuum is investigated. We also analyse the velocity field of the ionized gas. Besides the two compact HII components of the main body we find a population o...

We present a multiwavelength study of a sample of far-infrared (FIR) sources detected on the Herschel broad–band maps of the nearby galaxy M33. We perform source photometry on the FIR maps as well as mid-infrared (MIR), Hα, far-ultraviolet and integrated HI and CO line emission maps. By fitting MIR/FIR dust emission spectra, the source dust masses, temperatures and luminosities are inferred. Th...

As part of a multi-faceted program to investigate the origin and early evolution of sub-stellar objects, we present high-resolution Keck optical spectra of 14 very low mass sources in the IC 348 young cluster and the Taurus star-forming cloud. All of our targets, which span a range of spectral types from M5 to M8, exhibit moderate to very strong Hα emission. In half of the IC 348 objects, the H...