Point‐Source Extraction with MOPEX

Makovoz, David; Marleau, F.

doi:10.1086/432977

Cited by 306 publications

(314 citation statements)

References 12 publications

Supporting

Mentioning

312

Contrasting

Order By: Relevance

“…1, the Spitzer IRAC maps cover ≈87% of the area of our Herschel maps. We performed point source detection and photometry in these IRAC mosaics, using the Astronomical Point source EXtractor (APEX) module of the MOsaicker and Point source EXtractor package (MOPEX; Makovoz & Marleau 2005), as described in Ohlendorf et al (2012a).…”

Section: Spitzer Irac Datamentioning

confidence: 99%

Herschelfar-infrared observations of the Carina Nebula complex

Gaczkowski

Preibisch

Ratzka

et al. 2012

A&A

View full text Add to dashboard Cite

Context. The Carina Nebula represents one of the largest and most active star forming regions known in our Galaxy. It contains numerous very massive (M > ∼ 40 M ) stars that strongly affect the surrounding clouds by their ionizing radiation and stellar winds. Aims. Our recently obtained Herschel PACS and SPIRE far-infrared maps cover the full area (≈8.7 deg 2 ) of the Carina Nebula complex (CNC) and reveal the population of deeply embedded young stellar objects (YSOs), most of which are not yet visible in the mid-or near-infrared. Methods. We study the properties of the 642 objects that are independently detected as point-like sources in at least two of the five Herschel bands. For those objects that can be identified with apparently single Spitzer counterparts, we use radiative transfer models to derive information about the basic stellar and circumstellar parameters. Results. We find that about 75% of the Herschel-detected YSOs are Class 0 protostars. The luminosities of the Herschel-detected YSOs with SED fits are restricted to values of ≤5400 L , their masses (estimated from the radiative transfer modeling) range from ≈1 M to ≈10 M . Taking the observational limits into account and extrapolating the observed number of Herschel-detected protostars over the stellar initial mass function suggest that the star formation rate of the CNC is ∼0.017 M /year. The spatial distribution of the Herschel YSO candidates is highly inhomogeneous and does not follow the distribution of cloud mass. Rather, most Herschel YSO candidates are found at the irradiated edges of clouds and pillars. The far-infrared fluxes of the famous object η Car are about a factor of two lower than expected from observations with the Infrared Space Observatory obtained 15 years ago; this difference may be a consequence of dynamical changes in the circumstellar dust in the Homunculus Nebula around η Car. Conclusions. The currently ongoing star formation process forms only low-mass and intermediate-mass stars, but no massive (M > ∼ 20 M ) stars. The characteristic spatial configuration of the YSOs provides support to the picture that the formation of this latest stellar generation is triggered by the advancing ionization fronts.

show abstract

Section: Spitzer Irac Datamentioning

confidence: 99%

Herschelfar-infrared observations of the Carina Nebula complex

Gaczkowski

Preibisch

Ratzka

et al. 2012

A&A

View full text Add to dashboard Cite

show abstract

“…The Collinder 69 map was broken into two segments, one offset west of the star λ Ori -a very bright O8 III -and the other offset to the east, with the combined image covering an area of 57 × 61.5 , leaving the star λ Ori approximately at the center. Each of the IRAC images from the Spitzer Science Center pipeline were corrected for instrumental artifacts using the IDL code provided by the Spitzer Science Center and then combined into mosaics at each of the four bandpasses using the MOPEX package (Makovoz & Marleau 2005). Note that the IRAC images do not cover exactly the same FOV in all bands, providing a slice north of the star with data at 3.6 and 5.8 μm, and another slice south of it with photometry at 4.5 and 8.0 μm.…”

Section: The Spitzer Datamentioning

confidence: 99%

XMM-Newtoninvestigations of the Lambda Orionis star-forming region (XILO)

Barrado

Stelzer

Morales-Calderón

et al. 2010

A&A

View full text Add to dashboard Cite

Context. This is the first paper of a series devoted to the Lambda Orionis star-forming region, Orion's Head, from the X-ray perspective. Our final aim is to provide a comprehensive view of this complex region, which includes several distinct associations and dark clouds. Aims. We aim to uncover the population of the central, young star cluster Collinder 69, and in particular those diskless Class III objects not identified by previous surveys based on near-and mid-infrared searches, and to establish the X-ray luminosity function for the association. Methods. We have combined two exposures taken with the XMM-Newton satellite with an exhaustive data set of optical, near-and mid-infrared photometry to assess the membership of the X-ray sources based on different color-color and color-magnitude diagrams, as well as other properties, such as effective temperatures, masses and bolometric luminosities derived from spectral energy distribution fitting and comparison with theoretical isochrones. The presence of circumstellar disks is discussed using mid-infrared photometry from the Spitzer Space Telescope. Results. With an X-ray flux limit of ∼5 × 10 −15 erg/cm 2 /s we detected a total of 164 X-ray sources, of which 66 are probable and possible cluster members. A total of 16 are newly identified probable members plus another three possible new members. The two XMM-Newton pointings east and west of the cluster center have allowed us to verify the heterogeneous spatial distribution of young stars, which is probably related to the large scale structure of the region. The disk fraction of the X-ray detected cluster sample (complete down to ∼0.3 M ) is very low, close to 10%, in remarkable contrast to the low-mass stellar and substellar population (mostly undetected in X-rays) where the disk fraction reaches about 50%. The X-ray luminosity function of Collinder 69 in different mass bins provides support for an age of several Myr when compared with other well known young associations. Conclusions. The X-ray properties of the young stars in Collinder 69 resemble those found in other young stellar associations, with saturation at log (L x /L bol ) ∼ −3 and low fractional X-ray luminosities for stars with M ≥ 2 M . With our improved cluster census we confirm previous reports on the untypically low disk fraction compared to other clusters of several Myr age. The different disk fractions of X-ray detected (essentially solar-like) and undetected (mostly low-mass stars and brown dwarfs) members can be understood as a consequence of a mass-dependence of the time-scale for disk evolution.

show abstract

“…We used the MOPEX software suite v18.1.5 (Makozov & Marleau 2005) to assemble mosaics of the individual images, with a pixel scale of 1.22 /pixel. The MIPS images were obtained in photometry mode at 24 μm (silicon-based array) and 70 μm (germanium-based detector).…”

Section: Spitzer Observationsmentioning

confidence: 99%

The circumstellar envelopes of the Cepheids $\mathsf{\ell}$ Carinae and RS Puppis

Kervella¹,

Mérand

Gallenne

2009

A&A

View full text Add to dashboard Cite

Context. Compact circumstellar envelopes (CSEs) have been detected around several Cepheids by interferometry. In particular, observations with the VINCI instrument revealed in 2006 a compact envelope around the long period Cepheid Car (P = 35.5 days). Another Cepheid, RS Pup (P = 41.4 days), presents a large (≈2 ) circumstellar nebula scattering the Cepheid light in the visible. These envelopes are particularly interesting for two reasons: their presence could impact the Cepheid distance scale, and they could imply stellar mass loss. Aims. Our goal is to establish the spatial and spectral properties of the CSEs of Car and RS Pup. This is done through a parametrization of the envelopes in terms of fractional flux (with respect to the star) and angular size. Methods. We retrieved archival Spitzer images of the two stars (λ = 3.5−70 μm), and obtained new diffraction-limited imaging with the VLT/VISIR camera in BURST mode (λ = 8.6−11.9 μm), as well as interferometric observations with the VLTI/MIDI beam combiner (λ = 8−13 μm). This combination of single-telescope and interferometric techniques allows us to probe the envelopes of the two Cepheids over a broad range of angular scales, from arcminutes to milliarcseconds. Results. The circumstellar envelope of RS Pup is resolved spatially at 24 and 70 μm by Spitzer, and around 10 μm by MIDI and VISIR. The envelope of Car appears much more compact, and is resolved only in the VISIR and MIDI observations. The infrared excesses we detect around RS Pup and Car are both very significant, but differ considerably in spectral and spatial properties. We detect a warm component in the CSE of both stars at a spatial scale of a few 100 to a few 1000 AU. In addition, RS Pup presents a very large (several 100 000 AU) and cold (≈40 K) dusty envelope. Conclusions. The observed properties of the CSEs lead us to propose that the cold dust content of the large reflection nebula surrounding RS Pup has an interstellar origin, while the warm CSEs of the two stars were created by ongoing stellar mass loss. We also speculate that the NGC 7023 reflection nebula surrounding the Herbig Be star HD 200775 is an analogue of RS Pup at an age of 100 000 years. The presence of CSEs around the two brightest long-period Cepheids is an indication that many long-period members of this class, if not all, could be surrounded by warm circumstellar envelopes created by mass loss. However, very large dusty envelopes such as that of RS Pup are probably less common, as according to our scenario, they require the presence of a high dust density in the interstellar medium (ISM) at the time of the formation of the Cepheid progenitor.

show abstract

Point‐Source Extraction with MOPEX

Cited by 306 publications

References 12 publications

Herschelfar-infrared observations of the Carina Nebula complex

Herschelfar-infrared observations of the Carina Nebula complex

XMM-Newtoninvestigations of the Lambda Orionis star-forming region (XILO)

The circumstellar envelopes of the Cepheids $\mathsf{\ell}$ Carinae and RS Puppis

Contact Info

Product

Resources

About