The Spitzer c2d Survey of Nearby Dense Cores VII: Chemistry and Dynamics in L43 (2009)
Chen, Jo-Hsin, Evans II, Neal J., Lee, Jeong-Eun, Bourke, Tyler L.
We present results from the Spitzer Space Telescope and molecular line observations of 9 species toward the dark cloud L43. The Spitzer images and molecular line maps suggest it has a starless core...
The Bolocam Galactic Plane Survey -- II. Catalog of the Image Data (2009)
Rosolowsky, Erik, Dunham, Miranda K., Ginsburg, Adam, Bradley, Eric Todd, Aguirre, James, Bally, John, ...
We present a catalog of 8358 sources extracted from images produced by the Bolocam Galactic Plane Survey (BGPS). The BGPS is a survey of the millimeter dust continuum emission from the northern...
Blanc, Guillermo A., Heiderman, Amanda, Gebhardt, Karl, Evans II, Neal J., Adams, Joshua
We investigate the relation between the star formation rate surface density (Sigma_SFR) and the mass surface density of gas (Sigma_gas) in NGC 5194. VIRUS-P integral field spectroscopy is used to...
The Spitzer c2d Survey of Nearby Dense Cores: VI. The Protostars of Lynds Dark Nebula 1221 (2009)
Young, Chadwick H., Bourke, Tyler L., Dunham, Michael M., Evans II, Neal J., Jorgensen, Jes K., Shirley, Yancy L., ...
Observations of Lynds Dark Nebula 1221 from the Spitzer Space Telescope are presented. These data show three candidate protostars towards L1221, only two of which were previously known. The infrared...
Kirk, Jason M., Ward-Thompson, Derek, Di Francesco, James, Bourke, Tyler L., Evans II, Neal J., Merín, Bruno, ...
We present Spitzer IRAC (~2 deg^2) and MIPS (~8 deg^2) observations of the Cepheus Flare which is associated with the Gould Belt, at an approximate distance of ~300 pc. Around 6500 sources are...
Terebey, Susan, Fich, Michel, Noriega-Crespo, Alberto, Padgett, Deborah L., Fukagawa, Misato, Audard, Marc, ...
We investigate the environment of the very low-luminosity object L1521F IRS using data from the Taurus Spitzer Legacy Survey. The MIPS 160 micron image shows both extended emission from the Taurus...
Evans II, Neal J., Dunham, Michael M., Jørgensen, Jes K., Enoch, Melissa L., Merín, Bruno, Van Dishoeck, Ewine F., ...
(Abridged) The c2d Spitzer Legacy project obtained images and photometry with both IRAC and MIPS instruments for five large, nearby molecular clouds. This paper combines information drawn from...
Properties of the Youngest Protostars in Perseus, Serpens, and Ophiuchus (2008)
Enoch, Melissa L., Evans II, Neal J., Sargent, Anneila I., Glenn, Jason
We present an unbiased census of deeply embedded protostars in Perseus, Serpens, and Ophiuchus, assembled by combining large-scale 1.1 mm Bolocam continuum and Spitzer Legacy surveys. We identify...
The Mid-Infrared Extinction Law in the Ophiuchus, Perseus, and Serpens Molecular Clouds (2008)
Chapman, Nicholas L., Mundy, Lee G., Lai, Shih-Ping, Evans II, Neal J.
We compute the mid-infrared extinction law from 3.6-24 microns in three molecular clouds: Ophiuchus, Perseus, and Serpens, by combining data from the "Cores to Disks" Spitzer Legacy Science program...
Dunham, Michael M., Crapsi, Antonio, Evans II, Neal J., Bourke, Tyler L., Huard, Tracy L., Myers, Philip C., ...
We present a search for all embedded protostars with internal luminosities < 1 solar luminosity in the sample of nearby, low-mass star-forming regions surveyed by the Spitzer Space Telescope c2d...
MAMBO Mapping of Spitzer c2d Small Clouds and Cores (2008)
Kauffmann, Jens, Bertoldi, Frank, Bourke, Tyler L., Evans II, Neal J., Lee, Chang Won
AIMS: To study the structure of nearby (< 500 pc) dense starless and star-forming cores with the particular goal to identify and understand evolutionary trends in core properties, and to explore the...
The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus (2008)
Enoch, Melissa L., Evans II, Neal J., Sargent, Anneila I., Glenn, Jason, Rosolowsky, Erik, Myers, Philip
We present an unbiased census of starless cores in Perseus, Serpens, and Ophiuchus, assembled by comparing large-scale Bolocam 1.1 mm continuum emission maps with Spitzer c2d surveys. We use the c2d...
Merin, Bruno, Jorgensen, Jes, Spezzi, Loredana, Alcala, Juan M., Evans II, Neal J., Harvey, Paul M., ...
We present c2d Spitzer/IRAC observations of the Lupus I, III and IV dark clouds and discuss them in combination with optical and near-infrared and c2d MIPS data. With the Spitzer data, the new sample...
The young population of the Chamaeleon II dark cloud (2008)
Spezzi, Loredana, Alcala', Juan M., Covino, Elvira, Frasca, Antonio, Gandolfi, Davide, Oliveira, Isa, ...
We discuss the results of the optical spectroscopic follow-up of pre-main sequence (PMS) objects and candidates selected in the Chamaeleon II dark cloud based on data from the Spitzer Legacy survey...
Alcala', Juan M., Spezzi, Loredana, Chapman, Nicholas, Evans II, Neal J., Huard, Tracy L., Jorgens, Jes K., ...
We discuss the results from the combined IRAC and MIPS c2d Spitzer Legacy survey observations and complementary optical and near infrared data of the Chamaeleon II (Cha II) dark cloud. We perform a...
The c2d Spitzer spectroscopic survey of ices around low-mass young stellar objects II: CO2 (2007)
Pontoppidan, Klaus M., Boogert, A. C. A., Fraser, Helen J., Van Dishoeck, Ewine F., Blake, Geoffrey A., Lahuis, Fred, ...
This paper presents Spitzer-IRS spectroscopy of the CO2 15.2 micron bending mode toward a sample of 50 embedded low-mass stars in nearby star-forming clouds, taken mostly from the ``Cores to Disks...
A Parameter Study of the Dust and Gas Temperature in a Field of Young Stars (2007)
Urban, Andrea, Evans II, Neal J., Doty, Steven D.
We model the thermal effect of young stars on their surrounding environment in order to understand clustered star formation. We take radiative heating of dust, dust-gas collisional heating,...
Padgett, Deborah L., Rebull, Luisa M., Stapelfeldt, Karl R., Chapman, Nicholas L., Lai, Shih-Ping, Mundy, Lee G., ...
We present maps of 14.4 deg^2 of the Ophiuchus dark clouds observed by the Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS). These high quality maps depict both numerous point...
Molecular Line Observations of the Small Protostellar Group L1251B (2007)
Lee, Jeong-Eun, Di Francesco, James, Bourke, Tyler L., Evans II, Neal J., Wu, Jingwen
We present molecular line observations of L1251B, a small group of pre- and protostellar objects, and its immediate environment in the dense C18O core L1251E. These data are complementary to...
Star Formation in Molecular Clouds? (2007)
Using studies of nearby star formation with Spitzer, I will argue that star formation is restricted to dense cores within molecular clouds. The nature of these dense cores and their connection to...
The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. IV. Lupus Observed with MIPS (2007)
Chapman, Nicholas L., Lai, Shih-Ping, Mundy, Lee G., Evans II, Neal J., Brooke, Timothy Y., Cieza, Lucas A., ...
We present maps of 7.78 square degrees of the Lupus molecular cloud complex at 24, 70, and $160\:\mu$m. They were made with the Spitzer Space Telescope's Multiband Imaging Photometer for Spitzer...
Lahuis, Fred, Van Dishoeck, Ewine F., Blake, Geoffrey A., Evans II, Neal J., Kessler-Silacci, Jacqueline E., Pontoppidan, Klaus M.
We present a survey of mid-infrared gas-phase lines toward a sample of 76 circumstellar disks around low mass pre-main sequence stars from the Spitzer "Cores to Disks" legacy program. We report the...
Harvey, Paul, Merin, Bruno, Huard, Tracy L., Rebull, Luisa M., Chapman, Nicholas, Evans II, Neal J., ...
We discuss the results from the combined IRAC and MIPS c2d Spitzer Legacy observations of the Serpens star-forming region. In particular we present a set of criteria for isolating bona fide young...
The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds VIII. Serpens Observed with MIPS (2007)
Harvey, Paul M., Rebull, Luisa M., Brooke, Tim, Spiesman, William J., Chapman, Nicholas, Huard, Tracy L., ...
We present maps of 1.5 square degrees of the Serpens dark cloud at 24, 70, and 160\micron observed with the Spitzer Space Telescope MIPS Camera. More than 2400 compact sources have been extracted at...
SHARC-II Mapping of Spitzer c2d Small Clouds and Cores (2006)
Wu, Jingwen, Dunham, Michael M., Evans II, Neal J., Bourke, Tyler L., Young, Chadwick H.
We present the results of a submillimeter survey of 53 low-mass dense cores with the Submillimeter High Angular Resolution Camera II (SHARC-II). The survey is a follow-up project to the Spitzer...
Porras, Alicia, Jørgensen, Jes K., Allen, Lori E., Evans II, Neal J., Bourke, Tyler L., Alcal{á}, Juan M., ...
We present IRAC (3.6, 4.5, 5.8, and 8.0 micron) observations of the Chamaeleon II molecular cloud. The observed area covers about 1 square degree defined by $A_V >2$. Analysis of the data in the 2005...
The Spitzer c2d Survey of Nearby Dense Cores: IV. Revealing the Embedded Cluster in B59 (2006)
Brooke, Timothy Y., Huard, Tracy L., Bourke, Tyler L., Boogert, A. C. Adwin, Allen, Lori E., Blake, Geoffrey A., ...
Infrared images of the dark cloud core B59 were obtained with the Spitzer Space Telescope as part of the "Cores to Disks" Legacy Science project. Photometry from 3.6-70 microns indicates at least 20...
Bourke, Tyler L., Myers, Philip C., Evans II, Neal J., Dunham, Michael M., Kauffmann, Jens, Shirley, Yancy L., ...
We present Spitzer Space Telescope observations of the "evolved starless core" L1521F which reveal the presence of a very low luminosity object (L < 0.07 Lsun). The object, L1521F-IRS, is directly...
Lee, Jeong-Eun, Di Francesco, James, Lai, Shih-Ping, Bourke, Tyler L., Evans II, Neal J., Spiesman, Bill, ...
We present a comprehensive study of a low-mass star-forming region,L1251B, at wavelengths from the near-infrared to the millimeter. L1251B, where only one protostar, IRAS 22376+7455, was known...
The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. III. Perseus Observed with IRAC (2006)
Jorgensen, Jes K., Harvey, Paul M., Evans II, Neal J., Huard, Tracy L., Allen, Lori E., Porras, Alicia, ...
We present observations of 3.86 sq. deg. of the Perseus molecular cloud complex with the Spitzer Space Telescope Infrared Array Camera (IRAC). The maps show strong extended emission arising from...
Connecting Dense Gas Tracers of Star Formation in our Galaxy to High-z Star Formation (2005)
Wu, Jingwen, Evans II, Neal J., Gao, Yu, Solomon, Philip M., Shirley, Yancy L., Bout, Paul A. Vanden
Observations have revealed prodigious amounts of star formation in starburst galaxies as traced by dust and molecular emission, even at large redshifts. Recent work shows that for both nearby spiral...
Spitzer Discovery of Very Low Luminosity Objects (2005)
Kauffmann, Jens, Bertoldi, Frank, Evans II, Neal. J.
The Spitzer Space Telescope allows for the first time to search systematically for very low luminosity (= 0.1 L_sun) objects (VeLLOs) associated with dense molecular cores. They may be the first...
Discovery of a Low Mass Bipolar Molecular Outflow from L1014-IRS with the Submillimeter Array (2005)
Bourke, Tyler L., Crapsi, Antonio, Myers, Philip C., Evans II, Neal J., Wilner, David J., Huard, Tracy L., ...
Using the Submillimeter Array we report the discovery of a compact low mass bipolar molecular outflow from L1014-IRS and confirm its association with the L1014 dense core at 200 pc. Consequently,...
Cieza, Lucas A., Kessler-Silacci, Jaqueline E., Jaffe, Daniel T., Harvey, Paul M., Evans II, Neal J.
We argue that classical T Tauri stars (cTTs) possess significant non- photospheric excess in the J and H bands. We first show that normalizing the spectral energy distributions (SEDs) of cTTs to the...
Comparisons of an Evolutionary Chemical Model with Other Models (2005)
Lee, Jeong-Eun, Evans II, Neal J., Bergin, Edwin A.
We compare an evolutionary chemical model with simple empirical models of the abundance and with static chemical models. We focus on the prediction of molecular line profiles that are commonly...
Modeling the Physical Structure of the Low Density Pre-protostellar Core Lynds 1498 (2005)
Shirley, Yancy L., Nordhaus, Miranda K., Grcevich, Jana M., Evans II, Neal J., Rawlings, Jonathan M. C., Tatematsu, Ken'ichi
Lynds 1498 is a pre-protostellar core (PPC) and was one of the initial objects toward which molecular depletion and differentiation was detected. Despite the considerable scrutiny of L1498, there has...
Fragmentation and Evolution of Molecular Clouds. I: Algorithm and First Results (2005)
Martel, Hugo, Evans II, Neal J., Shapiro, Paul R.
We present a series of simulations of the fragmentation of a molecular cloud, leading to the formation of a cluster of protostellar cores. The purpose of these simulations is to address a specific...
Evolutionary Signatures in the Formation of Low-Mass Protostars (2005)
Young, Chadwick H., Evans II, Neal J.
We present an evolutionary picture of a forming star. We assume a singular, isothermal sphere as the initial state of the core that undergoes collapse as described by \citet{shu77}. We include the...
B335: A Laboratory for Astrochemistry in a Collapsing Cloud (2005)
Evans II, Neal J., Lee, Jeong-Eun, Rawlings, Jonathan M. C., Choi, Minho
We present observations of 25 transitions of 17 isotopologues of 9 molecules toward B335. With a goal of constraining chemical models of collapsing clouds, we compare our observations, along with...
Constraining the structure of the non-spherical preprotostellar core L1544 (2005)
Doty, Steven D., Everett, Sheila E., Shirley, Yancy L., Evans II, Neal J., Palotti, Matthew L.
A series of self-consistent, three-dimensional continuum radiative transfer models are constructed of the pre-protostellar core L1544, with the results compared with existing SCUBA and ISO data. The...
Pontoppidan, Klaus M., Dullemond, Cornelis P., Van Dishoeck, Ewine F., Blake, Geoffrey A., Boogert, Adwin C. A., Evans II, Neal J., ...
We present 5.2-37.2 micron spectroscopy of the edge-on circumstellar disk CRBR 2422.8-3423 obtained using the InfraRed Spectrograph (IRS) of the Spitzer Space Telescope. The IRS spectrum is combined...
Evolution of Chemistry and Molecular Line Profile during Protostellar Collapse (2004)
Lee, Jeong-Eun, Bergin, Edwin A., Evans II, Neal J.
Understanding the chemical evolution in star-forming cores is a necessary pre-condition to correctly assess physical conditions when using molecular emission. We follow the evolution of chemistry and...
Probing Pre-Protosellar Cores with Formaldehyde (2004)
Young, Kaisa E., Lee, Jeong-Eun, Evans II, Neal J., Goldsmith, Paul F., Doty, Steven D.
We present maps of the 6 cm and 1.3 mm transitions of formaldehyde toward three cold, dense pre-protostellar cores: L1498, L1512, and L1544. The 6 cm transition is a unique probe of high density gas...
From Molecular Cores to Planet-forming Disks with SIRTF (2003)
The SIRTF mission and the Legacy programs will provide coherent data bases for extra-galactic and Galactic science that will rapidly become available to researchers through a public archive. The...
A CS J=5-4 Mapping Survey Towards High-mass Star Forming Cores Associated with Water Masers (2003)
Shirley, Yancy L., Evans II, Neal J, Young, Kaisa E., Knez, Claudia, Jaffe, Daniel T.
We have mapped 63 regions forming high-mass stars in CS J=5-4 using the CSO. The CS peak position was observed in C34S J=5-4 towards 57 cores and in 13CS J=5-4 towards the 9 brightest cores. The...
Indications of Inflow Motions in Regions Forming Massive Stars (2003)
Wu, Jingwen, Evans II, Neal J.
Observational evidence for inflowing motions in massive star forming regions has been extremely rare. We have made a spectroscopic survey of a sample of 28 massive star forming cores associated with...
From Molecular Cores to Planet-forming Disks: A SIRTF Legacy Program (2003)
Crucial steps in the formation of stars and planets can be studied only at mid-infrared to far-infrared wavelengths, where SIRTF provides an unprecedented improvement in sensitivity. We will use all...
Chemistry and Dynamics in Pre-Protostellar Cores (2002)
Lee, Jeong-Eun, Evans II, Neal J., Shirley, Yancy L., Tatematsu, Ken'ichi
We have compared the intensity distribution of molecular line emission with that of dust continuum emission, and modeled molecular line profiles in three different preprotostellar cores in order to...
Chemistry and Dynamics in Pre-Protostellar Cores (2002)
Lee, Jeong-Eun, Evans II, Neal J., Shirley, Yancy L., Tatematsu, Ken'ichi
We have compared molecular line emission to dust continuum emission and modeled molecular lines using Monte Carlo simulations in order to study the depletion of molecules and the ionization fraction...
The Physical Conditions for Massive Star Formation: Dust Continuum Maps and Modeling (2002)
Mueller, Kaisa E., Shirley, Yancy L., Evans II, Neal J., Jacobson, Heather R.
Fifty-one dense cores associated with water masers were mapped at 350 micron. These cores are very luminous, 10^3 < Lbol/Lsun < 10^6, indicative of the formation of massive stars. Dust continuum...
Submillimeter Dust Continuum Studies of Low and High Mass Star Formation (2002)
Shirley, Yancy L., Mueller, Kaisa E., Young, Chadwick H., Evans II, Neal J.
Studying the physical environments of low mass and high mass cores using dust continuum emission provides important observational constraints on theoretical models of star formation. The motivation...
Shirley, Yancy L., Evans II, Neal J., Rawlings, Jonathan M. C.
Seven Class 0 sources mapped with SCUBA at 850 and 450 micron are modeled using a one dimensional radiative transfer code. The modeling takes into account heating from an internal protostar, heating...
Photon Dominated Regions in Low UV Fields: A Study of The Peripheral Region of L1204/S140 (2001)
Li, Wenbin, Evans II, Neal J., Jaffe, Daniel T., Van Dishoeck, Ewine F., Thi, Wing-Fai
We have carried out an in-depth study of the peripheral region of the molecular cloud L1204/S140, where the far ultraviolet radiation and the density are relatively low. Our observations test...
Shirley, Yancy L., Evans II, Neal J., Mueller, Kaisa E., Knez, Claudia, Jaffe, Daniel T.
In this survey we have systematically mapped 63 cloud cores in the CS J = 5 -> 4 line towards a sample of high mass star forming cores with water masers (Plume et al. 1992, Plume et al. 1997) using...
Dust Continuum Observations of Massive Star Forming Regions (2001)
Mueller, Kaisa E., Shirley, Yancy L., Evans II, Neal J., Jacobson, Heather R.
We have observed 51 high mass star forming cores associated with water masers at 350 micron. The spectral energy distributions (SEDs) and dust continuum normalized radial intensity profiles were...
Dust and Molecular Emission from the S235 Star Forming Region (2001)
Lee, Jeong-Eun, Young, Chadwick H., Shirley, Yancy L., Mueller, Kaisa E., Evans II, Neal J.
We present the results of a multi-faceted study of the high-mass star-forming region S235. With the CalTech Submillimeter Observatory (CSO), we have observed and/or mapped over fifty molecular...
Early Phases and Initial Conditions for Massive Star Formation (2001)
Evans II, Neal J., Shirley, Yancy L., Mueller, Kaisa E., Knez, Claudia
Our knowledge of the initial conditions and early stages of high mass star formation is very limited. We will review recent surveys of regions in the early stages of massive star formation using...
CS J = 7 -> 6 Mapping of Massive Star Formation Regions Associated with Water Masers (2001)
Knez, Claudia, Shirley, Yancy L., Evans II, Neal J., Mueller, Kaisa E.
Twenty-four cores have been mapped in CS J = 7 -> 6 at the CSO. From the spectra we determine core sizes and virial masses. Combining results from the CS and dust continuum studies for M8E, we use...
Evans II, Neal J., Rawlings, Jonathan M. C., Shirley, Yancy L., Mundy, Lee G.
We have modeled the emission from dust in pre-protostellar cores, including a self-consistent calculation of the temperature distribution for each input density distribution. Model density...
Tracing the Mass during Low-Mass Star Formation. I. Submillimeter Continuum Observations (2000)
Shirley, Yancy L., Evans II, Neal J., Rawlings, Jonathan M. C., Gregersen, Erik M.
We have obtained 850 and 450 micron continuum maps of 21 low mass cores with SED's ranging from pre-protostellar to Class I (18K < Tbol < 370K), using SCUBA at the JCMT. In this paper we present the...
How to Identify Pre-Protostellar Cores (2000)
Gregersen, Erik M., Evans II, Neal J.
We have observed the HCO+ J=3-2 line toward 17 starless cores selected from the list of Ward-Thompson et al. (1994). Six of these cores have line asymmetries indicative of collapse. The excess of...
Studies of Low-Mass Star Formation with ALMA (2000)
ALMA will revolutionize the study of star formation by providing a combination of angular resolution and sensitivity that far exceeds that of present instruments. I will focus on studies of...
Does Infall End Before the Class I Stage? (1999)
Gregersen, Erik M., Evans II, Neal J., Mardones, Diego, Myers, Philip C.
We have observed HCO+ J=3-2 toward 16 Class I sources and 18 Class 0 sources, many of which were selected from Mardones et al. (1997). Eight sources have profiles significantly skewed to the blue...
Van Dishoeck, Ewine F., Evans II, Neal J., Bakker, Eric J., Blake, Geoffrey A.
The temperature, density and kinematics of the gas and dust surrounding the luminous young stellar object GL~2591 are investigated on scales as small as 100 AU, probed by 4.7 micron absorption...
New Protostellar Collapse Candidates: An HCO+ Survey of the Class 0 Sources (1997)
Gregersen, Erik M., Evans II, Neal J., Zhou, Shudong, Choi, Minho
We have observed 23 Class 0 sources in the HCO+ J=4-3 and 3-2 lines. The mean bolometric temperature of the 16 sources with well-determined values is 44 K and the mean luminosity is 5.7 L_sun,...
Dense Gas and Star Formation: Characteristics of Cloud Cores Associated with Water Masers (1996)
Plume, Rene, Jaffe, D. T., Evans II, Neal J., Martin-Pintado, J., Gomez-Gonzalez, J.
We have observed 150 regions of massive star formation, selected originally by the presence of a water maser, in the J = 5-4, 3-2, and 2-1 transitions of CS, and 49 regions in the same transitions of...
Carr, John S., Evans II, Neal J., Lacy, J. H., Zhou, Shudong
We have observed rovibrational transitions of acetylene and HCN near 13 microns in absorption toward GL2591. We also observed rotational lines of CS, HCN, H2CO, and HCO+. The combined data are...
Exteremely High Velocity Outflows (1993)
Choi, Minho, Evans II, Neal J., Jaffe, Daniel T.
Extremely high velocity (EHV) wings, with full widths of 72 to 140 km/s, are seen on the CO J=3-2 lines toward W3 IRS 5, GL 490, NGC 2071, W28 A2, GL 2591, S140, and Cepheus A. The results of our...