New H2 Jets in Monoceros R2

We are presenting a wide-field image of the Mon R2 star forming region obtained with WFCAM on UKIRT in the 2.12 micron filter centered on the H2 1--0 S(1) emission line. We report the discovery of 15 new H2 jets in Mon R2 and two in L 1646 and confirm most of these discoveries using archival Spitzer IRAC 4.5 and 8.0 micron images. We find that many of these protostellar jets are found in projection against the outflow cavities of the huge CO outflow in Mon R2, suggesting that the jets may be associated with an episode of star formation in Mon R2 triggered by this large, but now fossil, outflow. We also study the spatial distribution of small, localized reflection nebulae and find that these are distributed in the same way as photometrically identified Class I sources.Comment: 46 pages with 19 figures. Accepted for publication in The Astronomical Journa

An S-shaped outflow from IRAS 03256+3055 in NGC 1333

The IRAS source 03256+3055 in the NGC 1333 star forming region is associated with extended sub-millimeter emission of complex morphology, showing multiple clumps. One of these is found to coincide with the driving source of a bipolar jet of S-shaped morphology seen in the emission lines of H_alpha and [SII] as well as in the H2 emission lines in the K-band. Detailed images of the driving source at the wavelengths of H_alpha and [SII] and in the I, J, H, and K bands as well as a K-band spectrum and polarimetry are discussed. The near-infrared morphology is characterized by a combination of line emission from the jet and scattered light from a source with a steep continuum spectrum. The morphology and proper motion of the jet are discussed in the context of a binary system with a precessing disk. We conclude that the molecular core associated with IRAS 03256+3055 consists of several clumps, only one of which shows evidence of recent star formation at optical and near-infrared wavelengths.We also briefly discuss a second, newly found near-infrared source associated with a compact sub-millimeter continuum source near IRAS 03256+3055, and conclude that this source may be physically unrelated the cluster of molecular clumps.Comment: 25 pages, including 5 figures. Accepted for publication in The Astronomical Journa

Circumstellar Disks revealed by HH/KK Flux Variation Gradients

The variability of young stellar objects (YSO) changes their brightness and color preventing a proper classification in traditional color-color and color magnitude diagrams. We have explored the feasibility of the flux variation gradient (FVG) method for YSOs, using $H$ and $K$ band monitoring data of the star forming region RCW\,38 obtained at the University Observatory Bochum in Chile. Simultaneous multi-epoch flux measurements follow a linear relation $F_{H}=\alpha + \beta \cdot F_{K}$ for almost all YSOs with large variability amplitude. The slope $\beta$ gives the mean $HK$ color temperature $T_{var}$ of the varying component. Because $T_{var}$ is hotter than the dust sublimation temperature, we have tentatively assigned it to stellar variations. If the gradient does not meet the origin of the flux-flux diagram, an additional non- or less-varying component may be required. If the variability amplitude is larger at the shorter wavelength, e.g. $\alpha < 0$, this component is cooler than the star (e.g. a circumstellar disk); vice versa, if $\alpha > 0$, the component is hotter like a scattering halo or even a companion star. We here present examples of two YSOs, where the $HK$ FVG implies the presence of a circumstellar disk; this finding is consistent with additional data at $J$ and $L$. One YSO shows a clear $K$-band excess in the $JHK$ color-color diagram, while the significance of a $K$-excess in the other YSO depends on the measurement epoch. Disentangling the contributions of star and disk it turns out that the two YSOs have huge variability amplitudes ($\sim 3-5$\,mag). The $HK$ FVG analysis is a powerful complementary tool to analyze the varying components of YSOs and worth further exploration of monitoring data at other wavelengths.Comment: 5 pages, 5 figures, accepted for publication in Astronomy and Astrophysic

The broad-line region and dust torus size of the Seyfert 1 galaxy PGC50427

We present the results of a three years monitoring campaigns of the $z = 0.024$ type-1 active galactic nucleus (AGN) PGC50427. Through the use of Photometric Reverberation Mapping with broad and narrow band filters, we determine the size of the broad-line emitting region by measuring the time delay between the variability of the continuum and the H$\alpha$ emission line. The H$\alpha$ emission line responds to blue continuum variations with an average rest frame lag of $19.0 \pm 1.23$ days. Using single epoch spectroscopy we determined a broad-line H$\alpha$ velocity width of 1020 km s$^{-1}$ and in combination with the rest frame lag and adoption a geometric scaling factor $f = 5.5$, we calculate a black hole mass of $M_{BH} \sim 17 \times 10^{6} M_{\odot}$. Using the flux variation gradient method, we separate the host galaxy contribution from that of the AGN to calculate the rest frame 5100\AA~ luminosity at the time of our monitoring campaign. The rest frame lag and the host-subtracted luminosity permit us to derive the position of PGC50427 in the BLR size -- AGN luminosity diagram, which is remarkably close to the theoretically expected relation of $R \propto L^{0.5}$. The simultaneous optical and NIR ($J$ and $K_{s}$) observations allow us to determine the size of the dust torus through the use of dust reverberation mapping method. We find that the hot dust emission ($\sim 1800K$) lags the optical variations with an average rest frame lag of $46.2 \pm 2.60$ days. The dust reverberation radius and the nuclear NIR luminosity permit us to derive the position of PGC50427 on the known $\tau - M{V}$ diagram. The simultaneus observations for the broad-line region and dust thermal emission demonstrate that the innermost dust torus is located outside the BLR in PGC50427, supporting the unified scheme for AGNs. (Abstract shortened, see the manuscript.)Comment: 11 pages, 23 figures, accepted for publication in Astronomy and Astrophysic

Speckle Control with a remapped-pupil PIAA-coronagraph

The PIAA is a now well demonstrated high contrast technique that uses an intermediate remapping of the pupil for high contrast coronagraphy (apodization), before restoring it to recover classical imaging capabilities. This paper presents the first demonstration of complete speckle control loop with one such PIAA coronagraph. We show the presence of a complete set of remapping optics (the so-called PIAA and matching inverse PIAA) is transparent to the wavefront control algorithm. Simple focal plane based wavefront control algorithms can thus be employed, without the need to model remapping effects. Using the Subaru Coronagraphic Extreme AO (SCExAO) instrument built for the Subaru Telescope, we show that a complete PIAA-coronagraph is compatible with a simple implementation of a speckle nulling technique, and demonstrate the benefit of the PIAA for high contrast imaging at small angular separation.Comment: 6 figures, submitted to PAS

Variability of the NGC 1333 IRAS 4A Outflow: Molecular Hydrogen and Silicon Monoxide Images

The NGC 1333 region was observed in the H2 1-0 S(1) line. The H2 images cover a 5' x 7' region around IRAS 4. Numerous H2 emission features were detected. The northeast-southwest bipolar outflow driven by IRAS 4A was studied by combining the H2 images with SiO maps published previously. The SiO-H2 outflows are continuous on the southwestern side but show a gap on the northeastern side. The southwestern outflow lobe curves smoothly, and the position angle increases with the distance from the driving source. The base and the outer tip of the northeastern outflow lobe are located at positions opposite to the corresponding parts of the southwestern lobe. This point-symmetry suggests that the outflow axis may be drifting or precessing clockwise in the plane of the sky and that the cause of the axis drift may be intrinsic to the outflow engine. The axis drift model is supported by the asymmetric lateral intensity profile of the SiO outflow. The axis drift rate is about 0.011 deg yr-1. The middle part of the northeastern outflow does not exactly follow the point symmetry because of the superposition of two different kinds of directional variability: the axis drift of the driving source and the deflection by a dense core. The axis drift model provides a good explanation for the large deflection angle of the northeastern outflow. Other H2 emission features around the IRAS 4 region are discussed briefly. Some of them are newly found outflows, and some are associated with outflows already known before