Deep Near-Infrared Observations and Identifications of Chandra Sources in the Orion Molecular Cloud 2 and 3

We conducted deep NIR imaging observations of the Orion molecular cloud 2 and 3 using QUIRC on the 88-inch telescope of the University of Hawaii. Our purposes are 1) to generate a comprehensive NIR source catalog of these star forming clouds, and 2) to identify the NIR counterpart of the Chandra X-ray sources that have no counterpart in the 2MASS catalog. Our J-, H-, and K-band observations are about 2 mag deeper than those of 2MASS, and well match the current Chandra observation. We detected 1448 NIR sources, for which we derived the position, the J-, H-, and K-band magnitude, and the 2MASS counterpart. Using this catalog, we identified the NIR counterpart for about 42% of the 2MASS-unIDed Chandra sources. The nature of these Chandra sources are discussed using their NIR colors and spatial distributions, and a dozen protostar and brown dwarf candidates are identified.Comment: 39 pages, 9 postscript figures, accepted for publication in A

Type-Ia Supernova Remnant Shell At Z=3.5Z=3.5 Seen In The Three Sightlines Toward The Gravitationally Lensed Qso B1422+231

Using the Subaru 8.2m Telescope with an IRCS Echelle spectrograph, we obtained high-resolution (R=10,000) near-infrared (1.01-1.38 \mu m) spectra of images A and B of the gravitationally lensed QSO B1422+231 (z=3.628) consisting of four known lensed images. We detected MgII absorption lines at z=3.54, which show a large variance of column densities (~ 0.3 dex) and velocities (~ 10 km/s) between the sightlines A and B with a projected separation of only 8.4h_{70}^{-1} pc at the redshift. This is the smallest spatial structure of the high-z gas clouds ever detected after Rauch et al. found a 20-pc scale structure for the same z=3.54 absorption system using optical spectra of images A and C. The observed systematic variances imply that the system is an expanding shell as originally suggested by Rauch et al. By combining the data for three sightlines, we managed to constrain the radius and expansion velocity of the shell (~ 50-100 pc, 130 km/s), concluding that the shell is truly a supernova remnant (SNR) rather than other types of shell objects, such as a giant HII region. We also detected strong FeII absorption lines for this system, but with much broader Doppler width than that of \alpha-element lines. We suggest that this FeII absorption line originates in a localized FeII-rich gas cloud that is not completely mixed with plowed ambient interstellar gas clouds showing other \alpha-element low-ion absorption lines. Along with the Fe richness, we conclude that the SNR is produced by an SNIa explosion.Comment: 16 pages, 15 figures, to be published in The Astrophysical Journa

Discovery of Extremely Embedded X-ray Sources in the R Coronae Australis Star Forming Core

With the XMM-Newton and Chandra observatories, we detected two extremely embedded X-ray sources in the R Corona Australis (R CrA) star forming core, near IRS 7. These sources, designated as XB and XA, have X-ray absorption columns of ~3e23 cm-2 equivalent to AV ~180 mag. They are associated with the VLA centimeter radio sources 10E and 10W, respectively. XA is the counterpart of the near-infrared source IRS 7, whereas XB has no K-band counterpart above 19.4 mag. This indicates that XB is younger than typical Class I protostars, probably a Class 0 protostar or in an intermediate phase between Class 0 and Class I. The X-ray luminosity of XB varied between 29<log LX <31.2 ergs s-1 on timescales of 3-30 months. XB also showed a monotonic increase in X-ray brightness by a factor of two in 30 ksec during an XMM-Newton observation. The XMM-Newton spectra indicate emission from a hot plasma with kT ~3-4 keV and also show fluorescent emission from cold iron. Though the X-ray spectrum from XB is similar to flare spectra from Class I protostars in luminosity and temperature, the light curve does not resemble the lightcurves of magnetically generated X-ray flares because the variability timescale of XB is too long and because variations in X-ray count rate were not accompanied by variations in spectral hardness. The short-term variation of XB may be caused by the partial blocking of the X-ray plasma, while the month-long flux enhancement may be driven by mass accretion.Comment: 26 pages, 8 figures, To be published in ApJ in April 200

First Detection of NaI D lines in High-Redshift Damped Lyman-alpha Systems

A Near-infrared (1.18-1.35 micron) high-resolution spectrum of the gravitationally-lensed QSO APM 08279+5255 was obtained with the IRCS mounted on the Subaru Telescope using the AO system. We detected strong NaI D 5891,5897 doublet absorption in high-redshift DLAs at z=1.062 and 1.181, confirming the presence of NaI, which was first reported for the rest-frame UV NaI 3303.3,3303.9 doublet by Petitjean et al. This is the first detection of NaI D absorption in a high-redshift (z>1) DLA. In addition, we detected a new NaI component in the z=1.062 DLA and four new components in the z=1.181 DLA. Using an empirical relationship between NaI and HI column density, we found that all "components" have large HI column density, so that each component is classified as DLA absorption. We also detected strong NaI D absorption associated with a MgII system at z=1.173. Because no other metal absorption lines were detected in this system at the velocity of the NaI absorption in previously reported optical spectra (observed 3.6 years ago), we interpret this NaI absorption cloud probably appeared in the line of sight toward the QSO after the optical observation. This newly found cloud is likely to be a DLA based upon its large estimated HI column density. We found that the N(NaI)/N(CaII) ratios in these DLAs are systematically smaller than those observed in the Galaxy; they are more consistent with the ratios seen in the Large Magellanic Cloud. This is consistent with dust depletion generally being smaller in lower metallicity environments. However, all five clouds of the z=1.181 system have a high N(NaI)/N(CaII) ratio, which is characteristic of cold dense gas. We tentatively suggest that the host galaxy of this system may be the most significant contributor to the gravitational-lens toward APM 08279+5255.Comment: 22 pages, 6 Postscript figures, 3 tables, ApJ in press (Vol.643, 2 June 2006

Flabegraviera mundata Gravier 1906

&lt;i&gt;Flabegraviera mundata&lt;/i&gt; (Gravier, 1906) &lt;p&gt; &lt;i&gt;Flabelligera mundata&lt;/i&gt; Gravier, 1906, 537&ndash;538; Gravier 1907, 37&ndash;39, Pl. 4, Figs 31&ndash;32, Text figs 22&ndash;23; Gravier 1911, 110&ndash; 112, Pl. 8, Fig. 87; Benham 1921, 108&ndash;109; Monro 1939, 130; Hartman 1952, 233; Hartman 1953, 50; Hartman 1966, 37&ndash; 39, Pl. 11, Figs 1&ndash;4; Hartman 1967, 124; Hartman 1978, 170; Rozbaczylo 1985, 159; Hartmann-Schr&ouml;der &amp; Rosenfeldt 1989, 72; Knox &amp; Cameron 1998, 72, Figs 137&ndash;139.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Flabegraviera mundata&lt;/i&gt;: Salazar-Vallejo 2012, 43&ndash;44, Fig. 18.&lt;/p&gt; &lt;p&gt;(New Japanese name: Kibukure-habouki)&lt;/p&gt; &lt;p&gt;(Figs 3&ndash;4)&lt;/p&gt; &lt;p&gt; &lt;b&gt;Material examined.&lt;/b&gt; Nontype specimen. NSMT-Pol- 113161. Complete (some chaetae broken, dissected), sex undetermined, non-reproductive adult, Nishinoura (69&deg;00.4&acute;S, 39&deg;34.5&acute;E), 8 m depth, sandy mud, 16 Jan., 1981.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Description.&lt;/b&gt; Nontype (NSMT-Pol- 113161) 6.0 cm long, 1.1 cm wide, fusiform, covered by very thick tunic (Fig. 3 A). Tunic transparent, gel-like, covering whole body and posterior portion of cephalic cage; sediment grains not attached. Body papillated; papillae long, clavate, forming sheath around base of chaetae. Lobe on dorsum of chaetiger 1 absent. Dorsal and ventral surface irregular.&lt;/p&gt; &lt;p&gt;Prostomium low cone. Branchiae 5&ndash;7 rows, about 120 filaments per side, 3 mm long, decreasing in size ventrally, colorless in ethanol. Branchial plate crescent-like, bisected by well-developed caruncle. Palps long (8 mm), cylindrical, grooved, pink in ethanol. Four black eyes present. Lateral and dorsal lips well developed, ventral lip reduced. Nephridial lobes present.&lt;/p&gt; &lt;p&gt;Chaetigers 30 in number; chaetiger 1 comprising cephalic cage. Cephalic cage 0.7 cm long, exposed for anterior 0.2&ndash;0.3 cm (Fig. 3 B), about 1/10 body length (6/10 body width), comprising 36 notochaetae and 30 neurochaetae per side. Chaetal transition from cephalic cage to body abrupt.&lt;/p&gt; &lt;p&gt;Parapodia poorly developed, completely covered by tunic; notopodia and neuropodia widely separated. Gonopodial lobe absent.&lt;/p&gt; &lt;p&gt;Chaetal arrangement from chaetiger 1 (using &ldquo;u&rdquo; for upper, &ldquo;m&rdquo; for middle, and &ldquo;l&rdquo; for lower (cf. Salazar- Vallejo 2012)): ululumluml.... Notochaetae of single type, multiarticulated, 1.1&ndash;2.6 cm long, sickle-like, 4&ndash;6 per fascicle. Neurohooks in chaetigers 2&ndash;30 (Fig. 4 A), 3 per fascicle, multiarticulated, 0.6&ndash;1.1 cm long, dark orange, covered by cylindrical shaft; handle anchylosed basally and distally, articulated in between, with 17 articles, progressively longer towards distal end (Fig. 4 B); crest distinct, width: length = 1: 7.&lt;/p&gt; &lt;p&gt;Posterior end not exposed; pygidium simple; no anal cirri; anus without pigment.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks.&lt;/b&gt; The syntype specimens of &lt;i&gt;Flabegraviera mundata&lt;/i&gt; (Gravier, 1906) were collected from 40 m and other specimens from a 20&ndash;385 m depth range (Salazar-Vallejo 2012). Our specimen was collected from 8 m depth, making it the shallowest record of the species. The finding of this species and also &lt;i&gt;F. fujiae&lt;/i&gt; &lt;b&gt;sp. nov.&lt;/b&gt; in shallow water means good opportunities for future research on adaptation of annelids to extreme environments, since the locality can be sampled using SCUBA.&lt;/p&gt;Published as part of &lt;i&gt;Jimi, Naoto, Tsujimoto, Megumu, Watanabe, Kentaro, Kakui, Keiichi &amp; Kajihara, Hiroshi, 2017, A new species and the shallowest record of Flabegraviera Salazar-Vallejo, 2012 (Annelida: Flabelligeridae) from Antarctica, pp. 477-485 in Zootaxa 4221 (4)&lt;/i&gt; on page 481, DOI: 10.11646/zootaxa.4221.4.4, &lt;a href="http://zenodo.org/record/252505"&gt;http://zenodo.org/record/252505&lt;/a&gt