A Herschel [Cii] Galactic plane survey III: [Cii] as a tracer of star formation
Jorge L. Pineda1, William D. Langer1 and Paul F. Goldsmith1
1 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099,

USA
E-mail contact: Jorge.Pineda at jpl.nasa.gov
The [C ii] 158μm line is the brightest far–infrared cooling line in galaxies, representing 0.1 to 1% of their FIR continuum
emission, and is therefore a potentially powerful tracer of star formation activity. The [C ii] line traces different phases of theinterstellar medium (ISM), including the diffuse ionized medium, warm and cold atomic clouds, clouds in transition fromatomic to molecular, and dense and warm photon dominated regions (PDRs). Therefore without being able to separate thecontributions to the [C ii] emission, the relationship of this fine structure line emission to star formation has been unclear. We
study the relationship between the [C ii] emission and the star formation rate (SFR) in the Galactic plane and separate therelationship of different ISM phases to the SFR. We compare these relationships to those in external galaxies and local clouds,
allowing examinations of these relationships over a wide range of physical scales. We compare the distribution of the [C ii]
emission, with its different contributing ISM phases, as a function of Galactocentric distance with the SFR derived from radio
continuum observations. We also compare the SFR with the surface density distribution of atomic and molecular gas,including the CO–dark H2 component. The [C ii] and SFR are well correlated at Galactic scales with a relationship that is ingeneral agreement with that found for external galaxies. By combining [C ii] and SFR data points in the Galactic plane withthose in external galaxies and nearby star forming regions, we find that a single scaling relationship between the [C ii]
luminosity and SFR applies over six orders of magnitude. The [C ii] emission from different ISM phases are each correlatedwith the SFR, but only the combined emission shows a slope that is consistent with extragalactic observations. These ISM
components have roughly comparable contributions to the Galactic [C ii] luminosity: dense PDRs (30%), cold Hi (25%),
CO–dark H2 (25%), and ionized gas (20%). The SFR–gas surface density relationship shows a steeper slope compared to thatobserved in galaxies, but one that it is consistent with those seen in nearby clouds. The different slope is a result of the use of aconstant CO–to–H2 conversion factor in the extragalactic studies, which in turn is related to the assumption of constantmetallicity in galaxies. We find a linear correlation between the SFR surface density and that of the dense molecular gas.
Accepted by Astronomy and Astrophysics

1409.0537.pdf
SFRSFR[M⊙yr−1] = 7.5 × 10−54NLyc[photons s−1] estimated by Chomiuk & Povich (2011) assuming a Kroupa initial massfunction (Kroupa & Weidner 2003)

(1) the [Cii] luminosity and SFR are well correlated on Galactic scales with a relationship that is consistent with that found forexternal galaxies.
(2) dense PDRs (30%), cold Hi (25%), CO–dark H2 (25%), and ionized gas (20%).
(3) SF Regions in our Galaxy ~ nearby galaxies : log(SFR[M⊙yr−1])=(0.89±0.04)log(L[CII][erg s−1])−(36.3± 1.5), applies
over six orders of magnitude

Long-term photometric observations of pre-main sequence objects in the field of North
America/Pelican Nebula
I. Poljanci´c Beljan1, R. Jurdana-Sepi´c1, E. H. Semkov2, S. Ibryamov2, S. P. Peneva2 and M. K. Tsvetkov2
To broaden the search and study stars in the early evolutionary phase, we investigated a sample of 17 pre-main sequenceobjects previously detected as either H_ emission-line pre-main sequence stars or T Tauri variables located in the field 32 of
the North America/Pelican Nebula complex. Johnson-Cousins B, V,Rc, Ic magnitudes and mean color indices for theprogram stars are determined from more than 12400 measurements from archive photographic plates and from CCD datacollected at 7 observatories covering the period of almost 60 years from 1954 up to 2013. We complemented previously rare
insights on the photometry of the program stars and presented their photometric history, which for almost all program stars isthe first long term photometric monitoring on a timescale of 6 decades. Eight program stars are found to be classical T Tauri

stars of variability type II, while 6 program stars are weak-line T Tauri stars of variability type I. For the first time, periodicity
is found for three stars: V1716 Cyg indicates a 4.15 day period, V2051 Cyg indicates a 384 day period, and V521 Cyg aperiod of 503 days.

Turbulence sets the initial conditions for star formation in high-pressure environments
J.M. Rathborne1, S. N. Longmore2, J. M. Jackson3, J. M. D. Kruijssen4, J. F. Alves5, J. Bally6, N. Bastian2, Y. Contreras1, J.
B. Foster7, G. Garay8, L. Testi9,10,11 and A. J. Walsh12
1409.0935.pdf

Despite the simplicity of theoretical models of supersonically turbulent, isothermal media, theirpredictions successfully match the observed gas structure and star formation activity within
low-pressure (P=k < 105 K cm 3) molecular clouds in the solar neighbourhood. However, it isunknown if these theories extend to clouds in high-pressure (P=k > 107 K cm 3) environments, likethose in the Galaxy's inner 200 pc Central Molecular Zone (CMZ) and in the early Universe. Here
we present ALMA 3mm dust continuum emission within a cloud, G0.253+0.016, which is immersedin the high-pressure environment of the CMZ. While the log-normal shape and dispersion of its
column density PDF is strikingly similar to those of solar neighbourhood clouds, there is one important
quantitative difference: its mean column density is 1--2 orders of magnitude higher. Both the similarityand difference in the PDF compared to those derived from solar neighbourhood clouds matchpredictions of turbulent cloud models given the high-pressure environment of the CMZ. The PDF
shows a small deviation from log-normal at high column densities confirming the youth of
G0.253+0.016. Its lack of star formation is consistent with the theoretically predicted, environmentallydependent volume density threshold for star formation which is orders of magnitude higher than thatderived for solar neighbourhood clouds. Our results provide the first empirical evidence that thecurrent theoretical understanding of molecular cloud structure derived from the solar neighbourhood
also holds in high-pressure environments. We therefore suggest that these theories may be applicableto understand star formation in the early Universe.
We obtained a 3'x1' mosaic of the 3mm (90 GHz) dust continuum and molecular line emission acrossG0.253+0.016 using 25 antennas as part of ALMA's Early Science Cycle 0.
within the inner 200 pc of our Galaxy (the Central Molecular Zone, CMZ)

Discovery of a companion candidate in the HD169142 transition disk and the possibility ofmultiple planet formation
Maddalena Reggiani1, Sascha P. Quanz1, Michael R. Meyer1, Laurent Pueyo2, Olivier Absil3, Adam Amara1, Guillem
Anglada4, Henning Avenhaus1, Julien H. Girard5, Carlos Carrasco Gonzalez6, James Graham7, Dimitri Mawet5, Farzana
Meru1, Julien Milli5, Mayra Osorio4, Schuyler Wolff2 and Jose-Maria Torrelles8
1408.0813.pdf
We present L′ and J-band high-contrast observations of HD169142, obtained with the VLT/NACO AGPM vector vortex
coronagraph and the Gemini Planet Imager, respectively. A source located at 0”.156±0”.032 north of the host star (PA=7.4◦±11.3◦) appears in the final reduced L′ image. At the distance of the star (∼145 pc), this angular separation corresponds to aphysical separation of 22.7±4.7 AU, locating the source within the recently resolved inner cavity of the transition disk. Thesource has a brightness of L′=12.2±0.5 mag, whereas it is not detected in the J band (J >13.8 mag). If its L′ brightness arose
solely from the photosphere of a companion and given the J − L′ color constraints, it would correspond to a 28-32 MJupiterobject at the age of the star, according to the COND models. Ongoing accretion activity of the star suggests, however, that gas
is left in the inner disk cavity from which the companion could also be accreting. In this case the object could be lower inmass and its luminosity enhanced by the accretion process and by a circumplanetary disk. A lower mass object is moreconsistent with the observed cavity width. Finally, the observations enable us to place an upper limit on the L′-band flux of asecond companion candidate orbiting in the disk annular gap at ∼50 AU, as suggested by millimeter observations. If thesecond companion is also confirmed, HD169142 might be forming a planetary system, with at least two companions opening
gaps and possibly interacting with each other.

SourceInner gap

Bright rim

Annular gap

7mm emission

可能性１）ArfifactやBackground starやrimの可能性もあるが、
２）KH収縮中の星、the L′ luminosity suggests a mass of 35-80 MJupiter for an age of 3-12 Myrs (Grady et al. 2007),according to the COND models (Baraffe et al. 2003). その場合はJband でJ=13.6-13.7 magで検出されるはずだが未検出。
a 28-32 MJupiter object at 3 Myrs.ならよい。が、この質量では結構大きな54-59AU のギャップが生じるので、25AU程度なら10木星質量程度で良い。
３）形成中の惑星、降着luminosityによって明るくなる。

Annular gap中の天体はL,Jバンドでは見つかっていない。

An Ionized Outflow from AB Aur, a Herbig Ae Star with a Transitional Disk
Luis F. Rodr´ıguez1,2, Luis A. Zapata1, Sergio A. Dzib3, Gisela N. Ortiz-Le´on1, Laurent Loinard1, Enrique Mac´ıas4 andGuillem Anglada4
1408.7068v1.pdf

AB Aur is a Herbig Ae star with a transitional disk. Transitional disks present substantial dust clearing
in their inner regions, most probably because of the formation of one or more planets, although otherexplanations are still viable. In transitional objects, accretion is found to be about an order ofmagnitude smaller than in classical full disks. Since accretion is believed to be correlated with outflow
activity, centimeter free-free jets are expected to be present in association with these systems, at weaker
levels than in classical protoplanetary (full) systems. We present new observations of the centimeterradio emission associated with the inner regions of AB Aur and conclude that the morphology,orientation, spectral index and lack of temporal variability of the centimeter source imply the presenceof a collimated, ionized outflow. The radio luminosity of this radio jet is, however, about 20 times
smaller than that expected for a classical system of similar bolometric luminosity. We conclude that
centimeter continuum emission is present in association with stars with transitional disks, but at levels
than are becoming detectable only with the upgraded radio arrays. On the other hand, assuming thatthe jet velocity is 300 km s−1, we find that the ratio of mass loss rate to accretion rate in AB Aur is ∼0.1,
similar to that found for less evolved systems.
AB Aur is a Herbig Ae star at a distance of 144 pc
Fukagawa et al. (2004) revealed spiral arms of enigmatic origin in the disk.
Pi´etu et al. (2005) found that the dust disk is truncated at an inner radius of about 70 AU from thecentral star.